I went once with the intention of buying a few 22 rifles as gifts for friends/relatives who had expressed an interest in shooting.
Rusted, beat to death guns going for over new MSRP. Stupid people buying at stupid prices. I got a Marlin in 22 magnum for $75 only so I didn't feel like I wasted a day and that was near the tail end of the auction after most people left. This was in 2011 I believe.
Memorable moments:
Sporterized 10/22 - $500
Mini 14 - $900
Savage rifle with a Bushnell scope - $800
Rusted out and pitted Mosin that didn't look like it worked - $250 - A few weeks before the auction, my dad bought an unfired, cosmoline packed Mosin, cleaning kit, ammo pouch and a can of ammo for $200.
If you're really bored, have some time to kill and want to see some genuine stupidity from folks with more money than sense, I highly encourage going. It is an experience you won't forget.