There is of course the possibility that your park is on some very valuable land right in the path of progress... or not. Be that as it may be there are some general "rules of thumb" people use to get a ballpark valuation for a park from a strictly economic point of view. One such calculation I have seen used would be 23 x 250 x 12 x 10 x .7 which provides a $483,000 price. Even this number might be considered generous as it assumes 100% occupancy with 100% collections. Removing the last x .7 and offering an insane 10 times yearly gross income would only be $690,000. Another ballpark tool I have seen is 70 times one month's gross rent; 23 x 250 x 70 is $402,500.
Another way to look at it is from a cash flow standpoint. I'm sure you have a little cash cow there seeing as you do not have a mortgage payment. Your buyer will either get a loan or pay all cash. Assume your buyer puts 30% down and gets a bank loan instead of asking you to carry the note on your sales of 1.4 million. At 5%, 20 year amortization the mortgage payment is $6,467 which is a tad bit more than the $5,750 gross rent the park produces. Well, there is always the cash buyer. Let us assume full occupancy, no one is ever late, and only 20% expenses, in other words the dream of every park owner. The buyer's $1.4 million would then earn slightly under a 4% return per year. I think it is safe to say that someone with $1.4 million in cash most likely has the ability to generate a return better than 4%, such as investing in the MHC America fund for a passive 10% return (plus or minus).
Did the unsolicited offers include any down payment? If so, once they defaulted because their mortgage payment exceeded the gross income, never mind paying taxes, insurance and other pesky expenses, you could keep their down payment plus get the park back in foreclosure! Rinse and repeat -lol. Were by chance these other offers at or near 100% financing with you playing the sucker, I mean playing the role of banker? I would imagine such a buyer would bleed the park dry, never pay you a cent, and once you foreclosed you would have unpaid taxes, deferred maintenance etc.
Finally let's look at things from a different angle. Imagine again that perfect park; full occupancy, 20% expenses... that little cash cow would give you 23 x 250 x .8 x 12 months is $55,200 per year. But think of all the work you have making sure all 23 rent check deposits come in every month. If someone gave you $552,000 and you invested it in the afore mentioned MHC fund, or perhaps the Park Street Partners fund, you would still earn $55,200 but only have one deposit to verify each month! Think of all the time you'll save -lol. Of course, then again, why would anyone pay half a million dollars for your park when they can invest in one of those Mobile Home Park Funds themselves and earn the same 10% ROI without any work? So it would seem to me that a price well south of $500,000 would be needed to entice someone to purchase your park. Probably best you just kept it.