The general rule of thumb is to buy if you are going to use the RV more than 3 weeks per year. If you will use it less than 3 weeks, then it makes sense to rent. Other factors are storage costs which can be as high as $1,000 per year. Maintenance and repairs can average $800 per year, and depreciation is constant. One, two, or even three rentals in a year can easily cost less than the cost of ownership.