Well, gone is that brief period where you could grab people's Amiga hardware for pennies in the pound. It's an enthusiast's platform now and hardware's rare, particularly such as what this guy is selling.
If I had the money to spare, I'd buy it. And you can't guarantee SOMEONE among us will have the money to spare, so my guess is it'll sell.
If you calculate the cost of those components sold seperately these days then it's not so high really. And to have them all in one complete, nicely boxed package is worth the slight premium.
