My PC currently has a nVidia 260GTX graphics card as it's primary monitor, and a 210 running a pair of secondary monitors. I'm looking to upgrade the primary card to something newer (dropping the 210, and making the 260GTX the secondary unless there is a triple monitor card/system available), but I'm not willing to spend a huge amount of money. I don't play many high end games at the moment, the most recent ones being the likes of Skyrim and Minecraft. Although I am waiting for Elite: Dangerous which will likely be the most taxing game I'll have for a long time.
I've been using www.hwcompare.com as a (very rough) comparison guide, and I can't find much that is a worthwhile upgrade (roughly 25% improvement) from the 260gtx without costing around £150 for something like a 660gtx, which is unfortunately above my £100 budget.