the cd3k can be bought new in the 300-400 dollar range but.. if you want to go by list prices over 700 here is a few:
akg-K1000- list is like 900 iirc
ATH-w2002 -900 new but no longer in production, 700+ used
ue10 - 1000
Sennheiser he60/hev70 aka baby orpheus -Not sure how much the can alone would be worth (this is an amp/can combo) but this too is no longer in production, used price is about 800-1200.
Stax omega I - no longer in production but used price is about 800-1500
Grado ps-1 - 1,400 from todd
Stax omega II- list price is 1800 for japan but the us retail is more, not even sure what it is.
ATH-l3000 - ranges, 1800-2500
ATh-l3000 limited green- 2500-3000
Sony mdr-r10- list is 4,000 (but like most things on this can be had for cheaper)
Sennheiser he90- 7000, also has an amp the hev90 it came with like the he60/hev70 combo. Together the amp and the headphone are worth 14k. This is no longer in production but there still are a few demo's in stores.