@Derek Magdziak, you will be valuing based on a Discounted cash flow method. 

I'm also open to other methods of ventilation that I may not be aware of.

This is the "brrr" method.

There are tons out there with great methods on how to figure out how many jack studs are needed and how thick a header needs to be.

I've purchase most of my deals in the last 2 years via this method and haven't run into any issues but I'm definition interested in hearing why you say be careful.Josh

Use a mortgage / deed of trust, real estate contract or whatever method gives you title in your area.  

I'd suggest doing a search here and reading up on various methods and opinions.

If so - What is the best method to determining an appropriate offer without knowing how much damage exists that is both a good deal for me (20% after repair value equity is the goal) but not too much of a low ball to where they aren't willing to listen. 

The one unit that does not have a w/d hookup has a laundry room on the same floor.Hot tubs I can see as a liability, unless it was a high-end rental.I forgot to mention one of my main methods of sprucing up a rental.

"BTW : Your method is not newBTW2 : There are tons of golf deals out there that need new financing.