I'm not sure what part of the country you are in, but mine was $58 from the dealer, which had it in stock. The dealer I deal with is Walter's Merecedes Benz in Riverside, California. As for actually doin the job, it's not that hard and doesn't require a guide. You just have to drill out some rivets and replace them. Also, there is a hidden allen screw that must be removed to get the lock unit out.