If it's bass you want that's fine, that's your style; you can always eq it up. Unless, that is, the 'phone will distort to all hell below 100hz at high SPLs. I dare you to name an electrodynamic for 200$ that will respond as well to electrical damping mods and eq in maintaining as tight and linear elevated bass response as the HD800. The DT770, while not a bad headphone, doesn't come anywhere near the HD800 in any criteria I can think of (excepting a taste for a smiley eq tonality).
This is foregoing the pricing of headphones being more than an arbitrary optimization of what the market is willing to pay - the HD800s aren't cheap to make.