what are your top "audio bargins" in your system history?

Grace Digital Link internet Radio.

Musical Fidelity v90 dac

Shure m97xe cartridge

Audioquest type 4 speaker cable

Technics mk7 

All the above are value for your money, I love them and would recommend the above components/cable to anyone. Their prices pale in comparison to my other stuff, by a large margin, yet provide me with great enjoyment. Bought most of them on sale or at a discount, even better!

In 1982 I saw a pair of ESS TranStatics listed in The Recycler, priced at $400. They originally retailed for $1200 in the early-70's, when I had lusted for a pair.

The speaker is a 3-way, the highs reproduced by three RTR ESL tweeters (the same tweeters Infinity was using at the time in their Servo-Static and 2000A models), the mids by a KEF 5" B110 driver, the bass by the renown KEF B139 oval woofer (used by David Wilson in his original 1970's WAMM) in a transmissionline enclosure.

Still have 'em!

The early Classe integrateds deserve a mention.  CAP-100 etc.

Right now I can buy a Nakamichi CR-7A cassette deck for 800 dollars. I believe it's in good working order. Should I buy it and flip it?

To this day I have no idea why the seller priced a 9.5 out of 10 Rotel RHA-10 preamp at $300, but I do know it wasn’t stolen.

I hooked it up, turned it up, then looked it up; there was only one on sale in all the world, in Germany for $1300.