A general valuation formula many in the industry use is: # of economically occupied lots * monthly lot rent * 70% (assuming 30% of income goes to expenses, common for parks on city utilities) * 12 (months in a year) / desired cap rateFor this park at a 10 CAP (many parts go for lower cap rates now, but small parks might still go for a 10 CAP), that makes: 21*298*.7*12/.10 = $526K . 

We are going to utilize it as a short term rental.

I’m just trying to get a feel for how some of you vet tenants and the environmental you utilize so I can be more precise when I’m ready to pull the trigger 

The other concern would be if you pay utilities, this will increase water and electric bills.

Utilities you'll call and put in your name and water bill will stay with the property (at least here in Metro Detroit) but sellers will put some money with title in escrow in case they don't get a final water reading or pay that water bill before leaving. 

A lot of people use prop stream, I myself use batch skip tracing and drive for dollars for leads and utilize my local backyard.

And you need to make sure you are billing back no more than the amount the utility company billed you.

In Oklahoma the meter belongs to the utility company.They provide the meter and the meter base.

But if they were all 1990s in perfect condition, that's only a value of $70,000.So the absolute most this deal is worth is more like $175,000.But even then, there's the issue with well water and septic -- private utilities on parks that small is often a suicide mission as if one goes out the cost to put it back in service will destroy your numbers (remember that it costs the same to build a well to serve 100 lots as it does 10 lots).Just trying to keep you out of trouble.

We are collecting $4,160 in rent, which covers our $2,950 mortgage and the $1,000 in utilities/supplies/cleaning service.