Advice on buying a computer

Hello all,

You guys helped me out about 3 years ago in buying a computer from ebay. Thank you. I think I need to buy a new one now. From what I understand XP is going out so here's what I got and what I need.

I have about $220 and I use my computer for DDO (gaming) and just usual email, research, etc. I'd like to get at least 3gb RAM, my monitor is still good but don't mind getting another flat screen. I looked on ebay and saw some things that looked good? but I'm a tad hesitant. So, any advice or pointers would be greatly appreciated.

Thanks in advance.