If it's a local auction, those are the
BEST! I've picked up some amazing pieces for chump change (1980-D cent on a dime planchet graded PCGS MS63 for $8, 1839 O/O
Seated dime with die crack for $12, etc.). The real key to these is knowledge. They usually allow a couple of hours before the auction to inspect the lots. Use this time to thoroughly investigate what's being offered. Gold is usually not a bargain. The big boys show up for all the gold and bid high. It's those obscure pieces that you can cherry-pick.
Does the auction house have an online listing of all lots (most do)? Download this and price-out the lots ahead of time. This will help you avoid getting caught up in the bidding frenzy. Also,
DO NOT BE INFLUENCED BY THE AUCTIONEER'S HYPE!. They always start at some ridiculous price and then regress, shaking their heads that someone is getting a steal. Most of them have little if any numismatic knowledge. Also don't trust any grades marked on 2x2's or grades stated by the auctioneer. If in doubt ask to see the piece again during the bidding.
Take a price guide (
RedBook if that's all you have, Cherry-pickers guide if you have it and a good loupe). Oh, and be sure to drain your bladder before it all starts.

I went to another auction in early December. I spent around $400, took half the lots and listed them on
ebay and made $650. So I got around 15 coins that I wanted and $250 change.
