Drake

I didn't remember the info correctly, you're actually right. DLP is actually the better/cheaper buy for lifespan:

LIFESPAN

DLP manufacturers list the backlight bulb hours at around 80,000 hours. What's more, this bulb can be replaced for as little as $200 in some cases. Certain DLP TV displays require a technician to change their bulbs, and this will cost you more than the lamp itself. In other cases, though, the DLP is configured in a way that makes it easy for a layperson to replace burned-out bulbs. It all depends on the make and model of your DLP.

And, since DLP is a mirror and light technology, once the bulb is replaced, the DLP should perform as well as it did when it was brand new.

Plasma, by contrast, uses a small electric pulse for each pixel to excite the rare natural gases argon, neon, and xenon (a k a "phosphors") to produce the color information and light. As electrons excite the phosphors, oxygen atoms dissipate. These rare gases actually have a life and fade over time. Manufacturers of plasma have estimated the life of these phosphors to be about 60,000 hours. The life of the plasma display itself is usually determined by half-life of the phosphors. So at 30,000 hours the phosphors will be at their half-life, and the viewer will be seeing an image that has half the brightness capability that it did when originally purchased. This should be a good point at which to consider its life over. The gases in plasma TVs cannot be replaced. There is no phenomenon of "pumping" new gases into a plasma display.

Advantage: DLP

http://www.plasmatvbuyingguide.com/dlpvsplasmatv.html