I see people asking lots of complicated questions, but to put pricing into a ballpark area, it is more simple than that.
20 lots rented is $66,000 per year. At 40% expense ratio, NOI is $39,600. Assuming 9% cap rate, park is worth $440,000.
Now let’s consider the homes. If the average home is $9,000, homes are worth $180,000.
If you add the value of the park and homes, the value is $620,000. Thus, the price is fair based upon the assumptions.
Of course my analysis is based on assumptions that may differ for you. The difficult part is accurately determining the assumptions based on your situation.
Good luck.