I have attempted to research an upgrade for under $100 for my old integrated card, but it's very confusing, so I could do with any help you could give me.
I have a Compaq CQ5210F PC, with 3 GB of Ram, an AMD Athlon II X2 215 DualCore processor, and Windows 7 64 bit.
I would like to be able to play Starcraft II, Napoleon: Total War, and Elder Scrolls V: Skyrim (when it comes out). I'm not looking for mind-blowing graphics quality, but I'd like enough to be able to play them without lag and possibly at medium graphics.
I am planning on playing them with one 1366 x 768 monitor.
A good point, forgot about the PSU. Even so, I would want to get a 4850 for its price and performance and look to getting a better PSU that can cope - depending on the PSU you get it also means you have room for further upgrades as time goes on.
For example the XFX 650w PSU is $65 after rebate (I am so jealous of American prices!!). Obviously that with the card means $25 over budget, but it is a great PSU which will last for many years and be good to put in a whole new build in the future.
But, taking PSU in to account, assuming it is very weak and upgrading is not an option, the 5570 would be the best bet.