15 inch crt? if thats is wat you are thinking of they are tiny cos their actual viewing size is smaller. If you want a proper 15 inch go for 15 inch TFT, you can get them for around 250-300
if you are not a hardcore gamer go for a 16ms TFT. You can get them for around your budget and they are good for gaming (there is a bit of ghosting but it depends on which one you get).