If you have £100, don't go near a 6200. From www.ebuyer.com
, the cheapest 6600GT is £130. If you can afford the extra £30, it's well worth it - if not, go for a 6600 (non-gt). The 6200 are pretty awful compared to what else you can get for £100. And, as for the turbo cache versions, there the worst. They use system memory in conjunction with a small ammount of memory on the card itself (16, 32 or 64 depending on the mode, also, only for PCI expressl)
Get a GF 6600, big improvement over the 6200, and the turbo cache is even slower.