I see now you had the lot rent in the original post. This park, like most, has two main possibilities to increase in value; 1, raising rents; 2, filling lots. That is why it is important to know the market rents. That is key to calculating the added value to the resale value of the park from both 1 and 2.
If we say the rents could go to $225/month and expenses running at, say, 50% of income (it is such a small park, so I guess the expense ratio would be even higher then the usual 45% for well managed apartment buildings) then with all lots filled and all lots at market rents the park would have a NOI of,
16 lots X $225 rent = $3600 monthly income X 12 months = $43,200 annual income X 50% = $21,600 NOI.
I guess you you would have to sell at something like a 11 - 12% cap rate, since it is such a small park. That gives us $21,600 / .12 = $180,000 market value of the park at 100% of its potential.
That is a whooping $7k above what the owner is asking now. Given my assumptions, the whole deal is kind of a joke.
If you are looking at such small deals I guess you are just starting out. I would suggest you don’t limit yourself to Parks but also consider flipper homes and failed small apartment buildings. You can also build up your capital turning them around and they can usually be found easier then just limiting yourself to Park deals.