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

I found a Pioneer Elite CD player at my local Goodwill store for 5 bucks, sure I spent 11 dollars on a remote on EBay but it’s still a great deal, thing is built like a tank

+1 on the Spica TC50

I would have to say my entire system except my DAC. Everything was acquired selectively used so I have great quality components for much less than retail price.

Krell Duo 300 XD found on Offer Up for $3,000.  Guy purchased a random pallet and just wanted to make his money back.  It was on its way back from the factory for an update.  The amp retails for $13K.  That re-kicked off my audiophile journey.  Got some open box Forte IV's from Safe and Sound for $3K ($5K retail).  Freya + for $600 ($900 retail), an SVS PB4000 sub for $700 ($1,800 retail), package deal for various Shunyata Research cables and Danafrips Ares II at well below retail from OfferUp.

Aerial 10t speakers purchased for $1000 in 2005. Still keep these. They're champions

Thorens TD125 all original turntable in the og box $150 at church yard sale