Very interesting show, I like it. As for how realistic it is, I assume that these guys go to tons of auctions on a daily basis but they are editing out the boring ones and only showing us the ones of interest. There have been some boring ones though, like the furniture and kitchen appliances, but I guess every little thing adds up once you sell it, so that you at least break even.
I always wonder why the heck people didn't empty their storage lockers before letting them default. If you can't pay the rent, at least go there one last time to take the valuables or things you can sell for a good profit. Though in some cases it looks like the owner was probably an elderly person that passed away and their remaining family members either don't know or don't care about what's in the storage locker.