Many of those I have pondered myself. Grados are just too expensive in Europe compared to the US prices. As a general rule, I'm interested in HPs around the 250-300 Euro pricetag for full cans. I know I'd never spend the extra money to improve source and amplification as much as more costly cans would require to sound their best. Never spent more than 300 Euro so far, and I'm wishing to stick to that rule. I'm into good sound, but not so far as to forget price-to-performance ratio and the law of diminishing returns.
Anyway, for now I can't even allow myself to fork out the MRSP for the Momentum, so I guess I'll spend some more time with the HD650 and make up my mind about it.