Walker in the Waste is bad unless Dry Lich's LA is houseruled away. The capstone doesn't make you a Dry Lich for free; it merely qualifies you to become one via the Sere Rite and 100,000 gp worth of crafting (the template can only be applied to a WitW 10). The sample Dry Lich is a WitW 10, and gets the CR and LA adjustments of the template. I know it's mind-numbingly stupid to hit you with LA for a PrC's capstone, but I don't see anything indicating that the LA wouldn't apply (indeed, there's literally nothing else the LA could possibly apply to).