well, i did a bit of research and came up with a $90 solution. note that this was the absolute best PCI card i could find, and it still isn't very good. still, it should be able to run the Kotor games just fine.
the link:
http://www.newegg.com/app/ViewProductDesc.asp?description=14-131-411&depa=1)
if you need a lower priced card than that, i'm not too confident that you'd be able to find a good graphics board that will do anything very well. but i will refer you to a search i did on newegg.com that will give you a good idea on all your options.
the link:
http://www.newegg.com/app/ViewProduct.asp?submit=property&catalog=48&propertycodevalue=0,%200,%200,%203344,%200,%200,%2) 00,%200,%200,%200&minprice=&maxprice=200&mfrcode=0&DEPA=1&page=1&listStyle=2
hope that helps. :)