I was pretty active on Head-Fi at the time and snatched up this deal when someone posted it. I think the HD800 was still $1500 at the time.
Though that is probably not even my greatest "steal", which could be loosely seen at actually stealing. I bought the Fostex TH-900 from a relatively new online vendor, and they accidentally sent me 2 of them. I checked and legally in the US when a merchant sends you something you didn't order, you aren't required to send it back. I held onto it for a bit and that company never contacted me about it and I sold it new in box for $900. I guess they were too disorganized to notice.
I'm not all entirely lucky or wise with money. I bought the Hifiman Edition X on release for $1400 and similar tier headphones like Edition XS are less than $500 now. But I still like them enough for it to be a permanent part of my collection.
Purchased in the last month off Ali some 11.11 and Black Friday.
Moondrop Little White Bluetooth Neckband and Moondrop Chu II bundle.
3x Moondrop Space Travel + Case to use as stocking stuffers.
Shanling M0 Pro DAP