Yeah, video cards are pricey, expensive beasts, but there is a trick to them that many don't quite know. The sad thing is video cards priced $160 and under are typcially decent cards... at the time. However they just lack the raw power to last, and so anyone that buys a card for under $200 will typically need to buy another one within just a year or two to keep playing the newest games with high detail settings.
The trick is to save up, then when a new generation comes out buy one of the top two model cards. Sure it costs $500, and that's alot of money, but the card will offer enough power to run anything for the next several years easily. Ya can spend $400-500 once every 3-4 years, or spend $200 every year or two.
The x850 XT PE series is a good example, they still can offer some power despite being an extremely old card by todays standards. The 8800GTX is another one. It costs a foturne, but it offers performance exceeding that of two x1950XTX cards in crossfire. That card will likely have a useable lifespan of 3-5 years as it also comes with Shader Model 4.0 and DX10 tech onboard, which won't be outdated anytime soon. This October/November Nvidia will be releasing the G92 refresh part... same card, smaller process size, so even higher clocks and less power consumption than an XFX 8800 Ultra XXX Edition.
I learned this trick after buying a $160 9600XT... great card, but even then it could barely handle CS:S with HDR enabled a year later with medium to high settings. Buying the top end once it's released will let ya skip buying a card for the next generation of cards and their 2nd generation refreshed parts after that. A 7800GT of old offers the performance of todays 8600GT card. A 7600GT offers the performance of yesterdays top end 6800GT card. Even the fastest overclocked 8600GTS out there is outgunned in raw performance by yesterdays 7950GT 512mb card.