The TechZone has published an article about the way new video cards are marketed.

In case you haven't noticed, the high-end video cards are expensive with every release, and the same high-end video cards disappear from their pole position within 6 months or less due to another model replacing it. There are video card owners who feel betrayed after spending $700 on a graphics card, only to discover several months later the card can be purchased for half the amount. Are these consumers justified in being confused and at a loss for why their video card is outdated before their next birthday?

The New Marketing Of Video Cards