If I see Cincinnati Coin machines when I'm showing a property to a client, I tell them to project $0 laundry income for their pro forma, and just be pleasantly surprised if the arrangement with Cincinnati Coin works out in their favor.

People are buying on bubble numbers of the last 1 to 2 years and pro-forma the number like it will last another decade after they own it. 

So long as you get books - make sure the tenants are paying and you aren't just getting a pro-forma.

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.  

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.

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

I would not form a llc to start.

IE there is a big difference between spending too much on cars and embezzling form a former employer.

I have pro forma statements that I can send to you revealing what you can expect for income and expenses for certain homes in certain vacation home communities.