I have made many good purchases through Proxibid. Coins, antiques and firearms to name a few. However, it pays to do a little homework before bidding.
Here are my list of dont's:
1. Don't bid on items when there are no or too few photos, or if the description is not adequate.
2. Don't patronize any auction house that reserves the right to look at pre-bids
3. Don't patronize any auction house that reserves the right to bid themselves, or allows the consignee to bid on items.
4. Read the conditions of sale to look for the "hidden" conditions including shipping conditions.
If you are competing with the "floor" there is a good chance that the auction house is trying to pump up the final sale price.