I have no idea why some people on here want to show you how smart they are. The OP asked a simple question. If you have no idea what you spend just say so or better yet say nothing. Me, i spent 4 years sailing the caribbean and I can not tell you what i spent on maintenance. i just know i have less money now than i did when i started. But we have great memories too.
You can go on to Speedco's web site and they will give you a general idea as to what a yearly service will cost for the "bones" of your MH.
As for batteries and "systems" (ie AC, Frig, ect.) Those will be a little harder to figure (same as trying to figure it for your home).
Good luck and now i am going to have a sneakers because i get a little upset when i am hungry