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

Mine wasn’t a component at all, it was the about the $98 or so I spent buying a fiber transmitter receiver and cable to install in the Ethernet line just before my bluesound node. Wow what a difference! If I’d spent 5 times that much it’d still be a bargain. Now I’ve upgraded to an Esoteric Network Player and still use the fiber. Still wow, just a bigger wow! 

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.