First of all, when you do a master lease, it is better not to mention a % of rent. Use hard numbers. If you use a % it sounds more like a management company.
Honestly, I don’t see any reason at all to buy this house. There is not enough meat on the bones!
I’d consider doing a master lease but with all the deferred maintenance, that does not sound like a good idea unless the seller agrees to no payments for a year so the house can be fixed up.
A better way to deal with this property would be to get an OPTION for as little as possible – $80,000 max, Negotiate seller financing terms with no balloon preferred. . Then do a highest bidder sale for the highest down payment. You could probably sell to a retail buyer at $100,000. Perhaps get $10,000 down. It would be hard to get more down because the buyer needs cash to fix up the house. But if you negotiate good terms with seller financing, you could get a nice monthly cash flow with NO MANAGEMENT or LIABILITY. You could put a 2 or 3 year balloon on the buyer’s note so you’d get cashed out later. But if the market tanks, you might get the house back, then you could sell it again or just keep it as a rental
It’s a skinny deal.