Amiga goods are priced the way they are for one reason: because sellers know they can be. It's a vicious cycle: reseller acquires an Amiga part, checks the last sold price for it (or gets a valuation from community members,) asks equal or more, leaves it on the shelf until some Amiga user desperate enough comes along to buy it for that price, the next seller to have that part in stock takes notice, asks slightly more than that, and so on...
The hell of it is, you can't just tell Amiga fans to boycott the sellers, because Amiga equipment does wear out and there is no other way to get replacements...oy.