There are other ways around this such as seller financing or private money lending but that is an obstacle you should be aware of. 

Real estate investing often demands reserves for unforeseen expenses.

they're sitting, either because 1. they're not distressed enough, or 2. the seller won't budge off of their unrealistic price, or 3. something else is very, very off.hope this helps - happy to help further

But the real key is to find motivated sellers.

What is the range of broker commissions charged to the seller on a small park 10-60 spaces ( 1-8 M sales price)?

I see people without capital no experience or capital being taught to “help” desperate homeowners by tying up their property in a contract they have no way to successfully close without finding someone to pay more; costing the homeowner behind on their mortgage payments to lose valuable time that can easily lead to foreclosure; I see a program taught to students to take over a property ‘subject to”, leaving the seller unable to qualify for further mortgage financing, responsible for a loan secured by a property he no longer owns, and all held together by someone with 0 experience, limited or no capital, and no liability.  

When the housing market became seller friendly, I unloaded 5/6 of our long term rental units, paid off our house with that and invested in stocks and mutual funds…completely no fun, right??

Trust invests the cash to make the payments on the installment sale to the seller.

How could I determine how much demand there is?

I could keep it and rent it, rents are good and in high demand but just looking for a different property type.