The answers you are gonna get will vary greatly, based on the type of MH you choose. Buying new or used, Gas verses Diesel, tag or no tag, entry level or mid to upper level, doing it yourself or having someone do the maintenance for you. It's impossible to say. So the info you will get won't really help you much. What I can say is owning an expensive toy will cost you $$. We keep up on the maintenance right to a tee, some I do myself some I have others do. We don't really keep track of costs as we love traveling so whatever the costs are they are worth it to us. We feel we can afford it or we wouldn't be doing it. I think it will end up costing you more than you think it will in the long run, so I would plan for spending more rather than less. Think about that before you buy one. Good luck!!
Dave