Their claiming the wooden toilet seat was worn and needs to be replaced and charging $100, the last is for 10 walls which they claim have holes, scuff marks, stains and charging $1400.

No one factors in tenants completely trashing a house , after not paying rent for 6 months , and the rowhome 4 doors down is abandoned with a hole in the roof and when it rains it floods your basement . 

Certainly the hot potato is leaving a gaping hole in our evaluation!

@Patricia Smith - I spent numerous hours researching from multiple sources the whole LLC question and asset protection matter and all the rabbit holes it opens.

They check the exterior each time and seal any new holes, make recommendations about anything I might need to do to help prevent pests, place bait boxes around the perimeter and will go inside if needed.

If there's a hole, it may be a red flag.b) sensitivity analysis: I examine all the assumptions, and make sure I can live with the worst case scenarios.c) "Stall and see": if they are getting money over multiple years, and there is no penalty for investing later, I would usually wait so I get some real performance data, versus having to look at theoretical pro forma information.d) Recession stress test: I will not invest in anything, until I subject it to recession level stress and see if I can live with the result.

To do that I could cut a hole in the dry wall and turn it 90 degrees so people can use it from the hallway but there is a light switch for a nearby bathroom in the way so that would need to be moved into the bathroom as well.

Depending on the class of this property get rid of that sprayer too just close off the 4th hole on the sink with cover plate.  

A few holes in this idea:-  I don't know where to find fully amortized 30 year loans for properties you plan to flip.-  You're not accounting for any down payment on that $150,000 you're borrowing.-  You're not factoring in fixed costs -- purchase costs, holding costs, selling costs into your numbers.-  With Dodd-Frank, selling with owner financing to a homeowner can be very difficult.In general, buying, fixing and selling with owner financing can work, but your numbers need to be better, and you should focus on finding investors to sell to. 

Quote from @Ethen Royal: Different methods, but my policy is to get a monetary judgment.