Hi ya.
I have attended several Storage auctions. You are right they are a hit or miss kind of thing.
I have had some good luck on a few different PS auctions. I got over 500 golden Age comics that way..Saved myself mad cash.
I have seen people get cars, motorcycles ,ATVs ,Guns the best one was a huge safe that was crammed full of old gold jewelry and such.
The most I will spend is 75 bucks, but I have found an even better way to do PS auctions..Don't go in the summer (unless the auction is being held on a Hot day or a rainy day)
I get the best results on cold rainy winter days . There less people at them in the winter and even less if it's raining.
Now as far as the clean out some places only give you 24 hours to get the storage unit emptied the good ones give you a week.
If you go to PSA in the winter you will cut your cost bu 35 to 50% (due to the fact of less buyers)
It's also a way to find things you never wanted to see or let the light of day see.
Oh yeah it can also be a messy job cleaning out all the left behind treasure/trash.
I'll keep on attending them for as long as I have the extra cash or my wife tells me to knock it off.