I can tell you from personal experience, going from astro a40's (which are supposed to be *cough* better *cough* than the choices you listed) to products usually reccommended in this forum is night and day (though to be fair, a40's > lcd-2's + amp + dac should be night and day). Music went from being flat and dull to amazing. As for other choices, there's a thread on gaming headphones around here somewhere, the audiotechnica's ad7000 (open ones, maybe at7000, whatever), get reccomeneded for games due to huge open soundstage but they lack bass, but if you wanna rape people in cod with dolby headphone, which is basically soundhax compared to anything else, they're the way to go.
At your budget you're looking at what do you want to comprimise, what is more important, if gaming with an advantage in shooters is more important than bass, i'd go the Audiotechnicas, and if music is a higher priority, around that budget would probably be the m50 or something? But yeah, sell the razer's asap, they make good mice n keyboards and stuff, but they're really...really new to the headphone game. Either way get a clip on mic, problem solved. Thing is the lower down in price you go, the more things you usually have to comprimise on, I would if budget allowed, get a nice open, light sounding pair of headphones for gaming, for the dolby headphone zomg i just got a 37 kill streak in cod, then some ones with more body/impact/bass/slam (whatever term floats your boat) for tunes. Different tools for different jobs really.
And if you really 'need' a headset, the sennheiser pc360 is pretty much *the* way to go, but it's pricy.