@ quietstorm: have you tried listening to HD 25-1 IIs?
they might be right for your budget but i havent tried them, just read that they are quite good.
I owned Senn HD-215s and they isolated really well, but they aren't quite at the same level as the ones you mentioned. Cheaper though.
Hey guys, I'm trying to be pursuaded (or not pursuaded) into buying some good condition Pioneer SE-700s from ebay. Just wondering how piezos sound compared to modern 'phones and how they'd be for portable use with an amp and such?