I have never been to one ....I'm confident I can make good locker buys.

  Buying at storage auctions is a betting game.  A prospective buyer gets a brief look at the tip of an iceberg and an opportunity to bid on the whole thing.  One's ability to guesstimate the value of a locker - a function of experience - determines the risk of overpaying.    The risk and the size of working capital limits the maximum bid.   Going over the limit turns betting into gambling - a loser's game.   

My advice is to start small, buy a locker and completely dispose of its contents before buying the next one.  The longer you can stay in the game, the higher is your probability of success.  Good luck.

I am a small-time collector.  I buy stuff at estate auctions/tag sales, flea markets and garage/yard sales.  Looking to add storage lockers to the list.