So this christmas I think I'll be looking for a new monitor to replace my old DELL 20". It's a good monitor but I want to up the screen size and rez. I play swtor now primarily so this is what will be on the screen the most as far as gaming. I guess my question are these.

I've read that 27 inch monitors use the same rez as the 24 so you will get less quality resolution. So is going 27 inches worth it? I can't afford to go 30". I don't buy monitors often. It's been probably 6 or 7 years since I bought my current one so I would like to get something I'm happy with. I don't plan to watch movies or anything on this. I have a TV for that. Mostly this will be used as a computer monitor but I'd like the best quality for my budget wich is around 300 dollar range. I run windows 7 64, i5 25k, gtx460. Any suggestions would be appreciated.

Thanks in advance.