Estimating rarity or number of units in circulation by frequency on eBay

[orb85750]

I always wonder how rare a piece of Amiga hardware (or software) is.  Some stuff you see up on eBay all the time, while other items you're lucky to find a few times per year, or even less.  Has anyone devised a formula to estimate the number of units still in circulation based on frequency of appearance on eBay?  Seems like a rough formulaic estimate could be gotten with just a few reliable known data points.  Any leads on this idea?  Someone somewhere must have already done it.  -Dave

[Rudei]

Perhaps you should give it a go? :-)

Membership of sites may give an indication of active users but as for pieces of hardware, I guess that would very much depend on the actual hardware itself.

eg. A1200s - very common
    Blizzard 030s - quite common
    A1000s - very rare
    VideoToasters - rocking horse pooh
    Walker prototype - urban myth :-)

Rude!

[quarkx]

Rudei wrote:
Perhaps you should give it a go? :-)

Membership of sites may give an indication of active users but as for pieces of hardware, I guess that would very much depend on the actual hardware itself.

eg. A1200s - very common
    Blizzard 030s - quite common
    A1000s - very rare
    VideoToasters - rocking horse pooh
    Walker prototype - urban myth :-)

Rude!

In Canada is is quite A Different story, almost opposite.
A1200 -Rare
A500- very common
A500+ Good luck
A600 even rarer than a A1200
A2000 Very common
A1000 almost as common as A500 but slowing down in recent months.
Video toasters- common,
A3000 almost rare, but they do pop up from time to time
A4000 more common than the 3's

I think that IF seller's in the US, would even admit Canada is here, we would have much more at our disposal, but I would guess only about 1 in 10 US sellers will ship to Canada or at lease specify they will on Ebay.

[meega]

IF seller's in the US, would even admit Canada is here

It's well-known that Canada is not contiguous.  :lol:

[murple]

I really don't think that will give you an accurate picture of anything except rarity ON EBAY. It doesn't take into account the many sales and trades done over forums, web shops (AmigaKit etc), AmiBay, or CraigsList. Even if you got and combined statistics on all of that, it's only going to give you numbers from people who think Amigas are worth something and try to sell them to collectors. To many people, they're just old junk taking up space in the closet, and often end up in thrift shops or given away for free from people who are just grateful for somebody to "get rid of the junk." Let's not even think about stuff that just gets put in the trash.

Ebay also has a bizarre psychology that can artificially inflate prices on things that can be had elsewhere for much less, which can make things seem rarer than they are.

[KThunder]

@quarkx
"You do know that Canada is a separate country,right?" i was asked that question at the border when i tried to cross with just a drivers licence a few years back like i had been told i could after calling ahead.
shipping to many other countries is the same as shipping to Canada nowadays. like it or not it really isnt like shipping to "north montana" which i think kinda sucks.
ive bought amiga gear and other stuff from canada before and never had trouble, and i dont think its much of a hassle sending stuff there.
i dont think there is a direct correlation between items on ebay and items existing. unless you knew totals now and on ebay it would be tough to figure. the only totals we really have are original sales figures from many years ago

[dannyp1]

I believe EBay is probably a very good indicator of the rarity of Amiga items.  No one is trying to say EBay is the only place equipment is available or that there isn't a lot of items thrown in the dumpster.  But I can pretty much assure you that there are more A500's thrown in the dumpster than PIV's.  Why?  Because there are a lot more A500's floating around.  I will say that price alone on EBay is not the only indicator of rarity.  You also have to factor in desirability.

[quarkx]

KThunder wrote:
@quarkx
"You do know that Canada is a separate country,right?"

Oh, boy, that is VERY debatable- which I really don't want to open that topic. My point is there is so many seller from the US (about 40 to 60%) that have no idea how to make their Auction appear on (for example )e-bay .ca. Most are willing to ship to Canada, but they have to be asked.
Now there also is a small number that will ship worldwide, but State in the auction "I WILL NOT SHIP ELECTRONICS TO CANADA"
I fill out customs forms and ship worldwide on a weekly basis, custom forms take less than 2 minutes to fill out, but a lot of seller state it is not worth the hassel.

[orb85750]

Rudei wrote:
Perhaps you should give it a go? :-)

Membership of sites may give an indication of active users but as for pieces of hardware, I guess that would very much depend on the actual hardware itself.

eg. A1200s - very common
    Blizzard 030s - quite common
    A1000s - very rare
    VideoToasters - rocking horse pooh
    Walker prototype - urban myth :-)

Rude!

OK, so if nobody has done this so far, maybe I should give it a go once I have a little time.  It would be nice to know roughly how many of each model/unit was made in the first place, to get some decent data points.  For example, number of Commodore A1200, A2000, A2500, SX-64, etc.   Does anyone know of any good sources of the total production numbers for these and other systems.  Of course, they don't have to be just Commodore or Amiga stuff either, for the purposes of formulating an equation -- but I don't want to spend all my time looking up Atari ST crap (for example).  -Dave

[cv643d]

Sweden:

A500 - very common.
A500+ - slightly less common than A500 but not rare.
A600 - relatively common.
A1200 - common.
A1000 - not so common, a bit unusual, perhaps rare.
A2000 - a bit common.
A4000 - a bit common.
A3000 - slightly less common than A4000.
A3000T - rare.
A4000T - about as common as the A1000.
CD32 - relatively common.

[murple]

I sort of hope you don't do this, orb. It may be an interesting mental challenge but for the reasons I already gave (as well as periodic fluctuations... I think you'd need to collect statistics over a couple years at least to take into account the way things sometimes seem to hit ebay in waves), I don't think you're going to get really meaningful accurate data.

Problem is the minute you release the numbers, every douchey seller on ebay is going to start using your rarity stats as a justification to jack up their prices.

[orb85750]

murple wrote:
I sort of hope you don't do this, orb. It may be an interesting mental challenge but for the reasons I already gave (as well as periodic fluctuations... I think you'd need to collect statistics over a couple years at least to take into account the way things sometimes seem to hit ebay in waves), I don't think you're going to get really meaningful accurate data.

Problem is the minute you release the numbers, every douchey seller on ebay is going to start using your rarity stats as a justification to jack up their prices.

Well, I only wish I had such an influence on the free market!  I'm essentially trying to do a simple inversion.  If I have a few reliable data points regarding the number of items in circulation of, say, products X, Y, and Z and they come up on eBay with frequency f(X), f(Y), and f(Z), it would be nice to use eBay frequency of appearance for other products in order to estimate their total circulation.  Seems harmless enough to me.  But to be done well, I agree that it will require many data points and plenty of time watching eBay!

[mdv2000]

Rare? I would say good shape, non-yellowing working Amigas are getting rare.  Of course, the majority of people under 30 don't ever remember Amigas - I even have co workers who never heard of C64 - much less Amigas!  I have bought 2 working A500 recently on ebay from people who didn't really know what they where - they where cleaning out closets/garages of family members and ebayed them!


The other issue is why would anyone want one?  I wanted an Amiga cause I had one when I was in elementary/high school and always wanted another after mine died.  But besides someone who had one or a computer history buff, the desirability is slipping.

Amiga Computers where always niche and never mainstream compared to crappy PC clones.  Even the Apple machines of the time period didn't sell well - and Apple almost went under too!

Amiga's are great fun for me and anything related to them is desirable to me... but unless the cost of the PPC Amigas come down, even the hobbyist market will go away as they degrade....

But on the bright side, apps like WinUAE will be here a long time to come so I can show my grand kids the first real OS I ever used!

My 2 cents worth....