Two good listings of items and prices:
- https://www.allthingsheroscape.com/ - probably around the 33 percentile of eBay pricing, meaning 2/3 of stuff on eBay sells for equal or above his prices, and 1/3 of stuff on eBay sells for less. I would say take 25% off his prices and it would be the 50th percentile of what people usually sell for around here. For instance, RttFF sells for $55 on his site, which is on the lower-mid end of eBay pricing. But $40 (~27% off his price) is on the middle range on Heroscapers, and probably a "fair" price at least to me.
- Hextreme Heroscape Spreadsheet - has prices from eBay and Auggies from a couple years back as well as retail, but also a good place to keep track of all your stuff plus many other features.