Doing pro-formas for the 1st time takes way longer than for the 100th.

But you should be trying to pre-qualify with a bank so you know the interest rate for various mortgage scenarios into your pro-forma.  

In the old days you built a park and a MH dealer would fill it with models  and then sell those units in place.but with todays land prices and prices to develop the absorption is simply to slow to make them financially viable.. 250 spaced could take 10 plus years to fill.Financing for MH in parks is not what it used to be either. and cities basically do not like them either form a land planning standpointunless your going to develop with cash there is no financing either for this.

Last thing is to ALWAYS only offer based on ACTUALS, not pro forma.  

Once rehabbed, the 5 vacant units will bring this up to pro-forma 25% cap rate based on the above purchase price.

We are trying to come up with an attractive investment for and investor but since we have no way of knowing how much the property is worth, how can we form a fair deal structure?

If there aren't other assets or businesses in the LLC, you can "re-purpose" you can file another DBA as well.If there is any chance of prior liabilities, I would form a new LLC.

(Cash on cash roi/ monthly cashflow/ pro forma cap rate / etc)My properties at the moment are anywhere from 8% to 23% cash on cash returns, with cash flows ranging from $175 a month to $833 a month.

Then you can set up your plan as to how to hold title, form a TIC and rent them.

My GC walked the property today and he felt he couldn't do it for the pro forma amount.