You've said you're on a budget, but how much can you afford?
If you're into gaming, don't bother buying a card that isn't at least DX8, and preferably DX9 compatible (the Radeon 7500 isn't). GF4 MX cards are crap, don't buy into them falsely on the basis of them being GF4.
Get a 128Mb card if possible, as most new games will be using the larger RAM cards to display the textures to their best, such as Doom 3.
<a href="http://www.ebuyer.com/customer/products/index.html?action=c2hvd19wcm9kdWN0X292ZXJ2aWV3&product_uid=39927" target="_blank">The Radeon 9000</a> cards are a good buy, on a par with GF3 ti200 in performance and better image quality for under £71 inc.