A few that I have picked up,and some of my friends finds....
I had a Warwick Thumb 5, new, on finance.there was a mistake with the finance company,I ended up paying £250. About ten years ago.
I recently picked up a Mesa Boogie 2x15 diesel cab for £150.
My mate was fitting a P.A system in a church in the area a few years back,as he was feeding leads under te stage floor,he hit his elbow. Put his torch on and saw the word" MARSHALL" looking back at him. It was one of those plexi heads from the 70's. They told him he could have it,they didnt know it was there. He put £50 into their kitty.
My builder mate was converting some guys garage, when he went to give a quote, he noticed some amps. They got talking and the guy didnt play any more and told him he could have the lot. Most of it was crap but there was a mint custom Carlsbro 50 top in there,and it sounds amazing.
And attic guitars do exist.....I think the crack convertor bargains are a myth though. I check all the time but nothing!