This is the crux of the problem the industry faces. Used homes are hard to finance. You have to sell them cheaply enough that people can afford them. New $60k late-model $40k late 90's $20k (let's say) all the way on down to 1980's and 1970's original HUD-code stuff.
The customer may be able to buy it cheap but they still have to pay the lot rent. Say $700 is rental and $350 is lot rent. How do they purchase? Take over the maintenance and pay ... something ... over time . . . it's a mortgage. Have to pay all at once? Keep $700 per month but wink wink it's yours after [you take over maintenance]. Looks like a mortgage when things go bad. If they stop paying, you are in the same place you'd be if you were renting it to them for $700. Looks like rent when things go bad. There's really no difference between POH or TOH if the tenants are not paying the lot rent, because if they can't afford the lot rent then they can't afford to keep their TOH and you'll be stuck with it as a POH. After waiting for legal proceedings, etc. Foreclosure and Eviction and UDAAP and Oh! The Risk!
Tip #1 - Consider that it may be better to run straight rentals of POH, and "collect" and "dispose" of the rental units as you have to/are able to. You have more control over who is in and who is out. In exchange you get the maintenance responsibility. These things do depreciate.
Tip #2 - Demand cures a lot of woes.
Tip #3 - all deals have warts.