Audio deals you bought that seem impossible for the price?

I bought a Vincent SA31 pre amplifier at half price in a sale, never had Vincent before but needed a cheap pre amp. It was originally around AUD$1000 got it for AUD$550, great bargain. Got it home fired it up and noticed it was a little different to the box so thought maybe minor upgrade and whilst box said SA31 the unit had SA31MK on it so I thought mk1 vs mk2. Had in system for a week before I queried with the store (after visiting Vincent website), the young salesman was apologetic but maybe I could just keep what I had as they had now stopped selling Vincent? So a new SA31MK rep AUD$1900 for $550.

Silversmith Fidelium speakers @ $1200 for an 8’ pair is a screaming deal. They blew away my $6K cables and probably better very pricey cables.

Buying searching out the gems quality ,brand,build quality then totally upgrading 
myself 20 years modding xovers ,the weakest link in well over 80% of loudspeaker so important being the central nervous system of a Loudspeaker 
the mfg  feels ok is good enough ,out of site out of  mind , in electronics 
many brands Come to mind ,even some very $$ ones nice looking average parts 
quality inside , with over 40 years in Audio and owned a Audio store in the U.K 
I recommended many upgrades ,that’s how Dan Modwright made a name 
he hired top engineers to assist in upgrading the circuit with better parts quality .
currently looking at top quality speakers ,getting a lot of flac on Many loudspeakers even Big names going cheap in the Xover dept.

I got a pair of used Clearwater Audio Duet6 stand mount speakers for $800. They have Accuton ceramic tweeters and drivers, mundorf caps, Supra wiring, just top notch parts all the way and the cabinets I heard were built by Salk and are almost 30lb each. I haven’t heard a stand mount for under $5k that are better, maybe different but not better. I don’t even have a place to use them right now but even my wife said I should hang on to them for as long as I like, and she hates holding on to things. 

I buy floor demo models and second hand. I’ve saved at least 60%.