I forgot to address the part where you said try it for several months? If you are buying new and decide to sell after a year or so you will take a bad hit. In that case buy used. If you do try it and then only use the rig part time you may have $100 or more in monthly storage.
If you take your time and shop you can get into older FW in good condition for $10,000. If you sold it a year later you would have far less loss. They also say if you are not handy have a lot of money. Even if I wanted to spend my money and pay someone, I cant imagine going through that much hassle.
If shopping for used water damage is your number one concern. If you by new look it cover very carefully for potential water leaks. It's not uncommon for people to have water damage after a few years because the new rv leaked from day one.