I also only invest in houses with at least two bathrooms, so there is never a bathroom repair emergency.I had to replace a washing machine about 3 years ago. 

A story I tell sometimes: years ago one of our local utilities had their water main wash away in a hurricane.

It was unexpected because this unit was just reno'd and doesn't have a washing machine. 

It is applied almost like paint so all you would need to is power wash your existing flat roof and apply another coat.

Wash, Rinse, Repeat

As @Matthew Paul has said it is a low pressure wash that they do, make sure no one is going to crank a high pressure wash machine on your roof. 

Was he looking to sell the cabin?

The name is not ordinary and only 1 person came up with that name  The phone number is a Wash DC area code and all the crimes were in MD counties just outside DC . 

Wash, rinse, repeat.

Also, at those price ranges, I have seen where B hoods could go to C and then it is basically a wash cash flow vs declining equity, vacancies etc...Hopefully, your B hood is heading the opposite way so some possible appreciation can cover any future issues that may arise.