For that budget and that room size, I personally recommend Klipsch speakers as they are very efficient and can fill that large room with plenty of sound. Another very efficient option would be the Chase SHO-10's as a front left/center/right trio. That would be what I would do as I think that the SHO-10's are hands down the best LCR combo for your budget. You need to make sure that what ever speakers you end up going with, they need to be very efficient due to your large space because most speakers would have a hard time filling all of that space up with good sound. For the subwoofer(s) you honestly need 2 or more to fully pressurize that large room. I would look into offerings from companies such as HSU, SVS, Chase, Outlaw, and Epic. I highly recommend going with an internet direct brand as opposed to a big box brand because you will get substantially more performance for your money that way. I hope this helps!