Well, mine is a MOTORHOME, the kind that can drive around, and I bought it in cash (I may not MAKE a lot of money, but I am good with the money that I do make), its a 1975 model, so it has already finished dropping in value, and (judging ebay prices), I paid about $1000 below market value to begin with (I paid $1800 for it with 70,500 miles, fully working, with 6 new tires and 400 hours on the generator).
Trailers drop in value like rocks, and can't REALLY be moved (especially the newer ones, which are multisection and are usually damaged if you try to move them after initial install), so you are stuck with whatever lot rent they decide to toss at you. I won't ever be buying a trailer unless it comes on land, or if I have my own land already (sometimes you can get the older ones free if you are willing to have them moved).