Spend $111 and get the 128MB Ti 4200, if they still have em on sale. The delivery time is nothing short of amazing, I get most of my stuff in 2-3 days with regular shipping.
I’d strongly suggest you spring for a DirectX9 compliant card. DirectX9 support will be important if you want to run new games, such as soon-to-be-released Doom III. In the low end, you really have three videocard choices. The Geforce FX Ti5200 for $75, Geforce4 Ti4200 $90, and ATI Radeon 9500 for $130. The GFFX Ti5200 and R9500 support DirectX9, the GF4 Ti4200 does not. On the other hand, the GFFX Ti5200 performs very poorly, roughly on par with a Geforce4 MX card. If you’re determined to spend less than $100, then you have to decide between a Geforce FX Titanium 5200 and a Geforce4 Titanium 4200 based on what’s more important to you, performance or compatibility. I’d STRONGLY suggest you just spend the extra $30 and get an ATI Radeon 9500, though. This will give you DirectX9 support, as well as good performance.