The Geforce 3 will not support the latest direct X, but they are good cards still. All it will mean is that you probably won't be able to use all the effects in new games. (I've been using a Rage Fury for over 3 years and it can still handle most games). If you've found one at the right price then go for it. They are better cards than the Geforce 4 MX's. The Geforce 4 Ti 4200's can be found for around £100 now, but that's a bit over your budget.
click here and have a look at the Sapphire 9000 Pro's.