400 MS Points gets you 40 new tracks.
The Trials Evolution Riders of Doom DLC is now available to buy on Xbox LIVE, Ubisoft has announced.
Riders of Doom offers 40 new tracks set in Big Sands Lands, a new environment inspired by the end of the world, and a powerful motorbike dubbed the Banshee. The 40 tracks are comprised of 20 new Trials tracks, 10 new Skill Games, five new Supercross tracks and five new Tournament tracks.
Also included are hundreds of new editor objects, all for just 400 MS Points.
Source: Press release