Mine is next to nothing
-A gallon and a half of Pink antifreeze (about $7.00)
-I wash and condition the roof once a year, (about $15 for roof preservative)
-I grease the wheel bearings myself with a grease gun, (a few dollars for grease)
- We winter in it, so I have to buy one tank of propane a year ($30)
- black tank chemicals (about $40) for six months
Other than that, any thing can happen, but most of it if you are handy, you can take care of yourself.
I wouldn't buy a used trailer. that is a whole different ball game
Guy
