With that in mind, my thoughts are on a looming recession. 

@David M. for my deal I use a promissory note for my earnest money (this way I didn't have to put down actually cash money and the note was due at closing meaning that I would have to pay the note off at closing)  Now the buyer who is buying the deal from me is putting $4,000 non refundable deposit/ Earnest Money its all the same in this case  (which I will use that money to pay the seller my $1,000 dollar promissory note and I keep the $3,000 for myself if he doesn't perform) now keep in mind if I don't perform on my end to purchase the house within my time frame and contingencies the seller's only recourse is to keep my earnest money of $1,000. 

Here is the problem I have... now the Airbnb calculator on the site does not appear to work, so I am using the rental income calculator because, to my mind, the principals are very similar.

Be very mindful about your next steps.

If you go with an open mind (but tightly closed wallet) you most likely will pick up ideas for further study.The other benefit I've found is that you walk away energized and excited to contine the journey.

I'm not saying to not use income based valuation but just to keep in mind that there is a difference between theory and reality. 

The only one that comes to mind is Crushing It by Brian Murray.

@Stephen RookerA good rule of thumb to use is $100/sqft, though keep in mind there are a significant number of factors that will effect the end number, especially with multi unit construction.  

Specifically I’d like to know how you would present the offer I have in mind based on the information below.I am a newbie.4 unit class B multi-family in a class B location (close to downtown)List price – $299k.

I feel it’s better to proactive show potential sellers with this third-party validation to put their mind at ease.