Well I would say if it is wired try more in the 200 dollar to 300 dollar range, if it is wireless im up for going a bit higher. As far as amps and DACs are concerned, if I need one for surround audio (virtual surround whatever) I would need recommendations on those as well. If the amp and DAC in the wireless headphone setup are good, I have no problem using those.
These would pretty much be strictly for hooking up to my PC, console or TV. Basically for around my desk and bed, not out and about headphones.