Looking at the rental prices some hire firms apply, there has to be some contingency/additional insurance built in to cover damage/wear and tear and general maintenance, of course if you are are the sole user all of that comes out of your own pocket.
If it’s out ‘earning’ 25-35 weeks of the year that should offset at least a chunk of the cost of ownership…
I suppose it depends on how attached you are to the camper, how much you really expect to be using it, or if you can think of it more like a (mobile) holiday home/gitê than just your own little adventure vehicle.
Say you rent it out and only use it yourself a few times a year it could pay for itself within a few years, of course by the end of that period its going to have clocked up some significant mileage…