Move TOH into park, make home stay in my park

Let’s say someone wants to move his TOH (tenant owned home) into my park.

I pay for the moving and setup cost ±$5000.

What prevents that tenant from moving his home out of my park a few months later? Obviously, he would have to pay the moving cost if he wants to move his home out, but is there a way to keep that home in my park?

I would hate to spend $5000 only to see him move out a few months later.

Thank you.

We do a 5 yr agreement with the prospect before moving into the park that they will be responsible to pay back any monies prorated over that time if they left the park.

PM me if you want to see our agreement. This agreement has NOT been vetted by an attorney.