If you want to talk lucky, I hit a once-in-a-lifetime deal a few years back.
Walked into the local 2nd hand shop, and they had a set of four 15" PA speakers, with dented grilles over the drivers, grey carpet and plastic corners.
Looked at the drivers, and I thought "those look a bit like Tannoy dual-concentrics..."
Looked at the little plastic recessed dish on the front, and there's a couple of rotary switches for HF adjustment. Embossed between the switches: TANNOY.
They were on sale for £50 per pair. I paid £80 for all four and got them out of the shop as fast as humanly possible.
At the time, I needed the money more than the speakers, so I sold them on. There's a small part of me that wishes I'd kept them but, having heard those cabinets as well as other implementations of those drivers, I'm not sure they're worth the price tag they command - there are better performing drivers at that sort of money.