Good luck with this. I'd be interested to see how you compare with simply viewing completed listings on ebay and, for example, the back of retro gamer which has a marketplace guideline every month.
I agree with gklinger, a couple of tasters would be good, especially to show that you've got a handle on the more esoteric stuff.
Could you give us a clue on the price of a PAL Amiga 3000 in base configuration, and perhaps a couple of accelerators such as the WarpEngine (common) and the CSA Magnum 40/4 (not terribly common!)
I hope you see this as a positive comment, not merely sniping
- I'm trying for the first, not the second