Refurbished Sennheiser HD 439 for $34.99 on ebay from seller vminnovations.
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Looks like none are available, sadly.
Oops, looks like Adorama sold out of them too..
Sennheiser HD 380's on clearance at Best Buy (in store only) for $125.99. They're not the best SQ-wise, but they isolate pretty well and make for good travel headphones.
A couple deals I just came across on ebay:
Used T1 for $799
I know sonic sense has a better deal on new ones when you become a member but this one offers a 3 year warranty.
Used DT880 - 600 Ohm for $199 (can make an offer and probably get it slightly cheaper)
Open box T90 for $392