on my mrk 1 i just replaced both rear ones, cost 53 quid for the pair i think, took me a while to get the drums off as theyh were on tight, found out the brake cylinder was leaking so had to replace that and a brake line also, so new shoes and springs etc, but excluding the brake bits, it cost me the price of the bearings and a garage pulled the old bearings out and pushed the new ones in useing a propper tool for free.
so its ALOT cheaper to do it your self, if a garage charges per hour and then they have a hassle like i did getting rear hubs off etc, then ur price will go up loads...