Account Closed,Lenders typically start their own "wheels" in motion after the third missed payment, but it can still take a while before they get to the point of beginning the process of foreclosure.That said, Brian called it: offer him what he owes  - you decide if you want to give him any more than that as an incentive to cooperate.

I got the house for $31800 with a 10% down payment so I still owe $28620 with an interest rate of 4.42% (that can be adjusted in 5 years), and a monthly payment of $179.90.

If paying PMI, you can always find a mortgage calculator and input your own figures to get an estimate for monthly payments after your escrow account. 

what is typical for a down payment if someone owner finances?

If I buy property A using conventional loan with 20% down payment, 5% of purchase price as closing cost estimate and $7K in repair, I'm looking at out of pocket cash of approximately $30K.

It would most likely trigger the due on sale clause.A scenario that may work though is if the amount remaining on their mortgage is less than what you are willing to offer as a down payment or they were willing to pony up the difference.

So the $700 payment on a home that rents for $1200 is still a decent cash flow.

Your results will be better, albeit more work.You could also create a holdings company for all your entities as I have done with various digital enterprises.

Down payment?

This is what the contract says about the Non-Refundable Down Payment;  The Non-Refundable Down Payment in the amount of 10% shall apply towards Buyers purchase price or closing cost.