The price of this stuff has unfortunately skyrocketed in recent years, way back in 2004 I scored a fully loaded A4000 CSPPC /CVISION machine on the German eBay site for about £350, which is afar cry from today's prices when it probably costs near that now for just the graphics card alone.
The reason for these skyrocketing prices is HOARDERS. Thats right, guys out there (many on this board ) with multiple amigas fully loaded (that they dont even use!) with rare parts. Meanwhile, guys who really want rare parts to build an amiga again or to upgrade an old machine are pretty much screwed.
The irony is these very same guys start threads crying about ebay prices. How laughable.
Having said all this, we have to be proud that the Amiga platform commands high prices no atari, pc, or mac systems retain value like this.