If you're unfamiliar with WOOT, then you should know that the site's slogan is "One Day, One Deal," so this certainly won't be available tomorrow and it might sell out at any time today. It's the pressure of the limited-time offer that helps WOOT sell so much stuff. The WOOT price for the Valet 9104 4-Sensor TPMS is a hundred bucks, with a $5 shipping fee. Froogle's average price for this item on other sites is around $220. I've never shopped for an aftermarket TPMS and have no idea about the quality of the Valet system or how other brands compare, but if you've been considering a TPMS for your car, this seems like a good deal.
[Source: WOOT, Froogle]