Update 7/20: MassDrop recently put a limited supply of these back on sale, if you missed out last month.
Sennheiser’s HD 650 open back headphones are widely considered some of the best-sounding cans you can buy for under $1000, and the best chance to get them is when MassDrop drops a new shipment of the legendary HD 6XX.
The 6XX is basically exactly the same as the 650, but with a 6' cable rather than the original’s 10', which is actually a better length, in my opinion. The 650s are currently listed for $316 on Amazon, and have never been cheaper than $287, but MassDrop has a limited number units of the 6XX available for $250 $200, while supplies last.