Garage Sale Steals - What to look for?

Am I the only one that has that dream of tagging along with the wife to some garage sale, only to find some audio equipment for sale and the guy doesn't know what to ask for it, saying, "make me an offer"? The thought flashes, boy I'd like to run home to look it up on the 'net to be sure! You return home, find out it's a gem, return to the sale only to find out someone with knowledge purchased it and you wake up in a cold sweat! (Sorry, I got a little carried away there.)

A year or so ago I was interested in Nak decks and used to have such thougts of finding a deal, though I am rarely, if ever, at a garage sale.

A recent discussion on here about Threshold amps prompted me to create this post. What "legendary" piece of audio equipment would you like to pick up for next to nothing? (This way I can create a cheat sheet for my wallet! LOL)