Cheap cards are always a mystery. I sure wish I knew where I could get one.
Here is where I dream:
http://www.pricewatch.com/
Here is where I validate information that is available:
http://www.tomshardware.com/
I want the new Radeon with 256Mb also, but I to have a limited budget. If I had the budget for it, here is where I could get it:
http://www.krex.com/Ppmain.asp?sg=1&gr=1&it=33&si=4
If you are talking about heat and system resources, then it's time to upgrade. Learn and move into the world of case nodification also, it is way easy and allows your creative side to come out. Just be cautious when you are running the jig saw, and dremel tools.
Felix