i think maybe you live in a country with a great sennheiser presence. for me they are pretty much average price of over 500$ from online or street points, not big name stores which sell them for more.
that is indeed a very very cheap price. here i could go for them or w5000 for about the same price. personally, im not an at person, so the hd650 would be it but knowing that it can be had for almost half the price in (where are you?) - i would not pay that much for them
p.s. i love the cable for them if it is the same one as the one you can order from the store for us 13$. i got that and love it for hd600 - big thick juicy and very very well made - not going to fall apart ever probably!
damn, 300$. damn. if they were that price, i would think twice. i have the hd600 (well, i will when i get married as my wife to be has them!) that will complement my beyer dt880 and ultrasone dj1pro very well. funny, my used hg600 were 200$ usd. really... damn, 300$? i thought i got a good price on my hd600 (2 years ago)