As for roofs , I'd say leave it to the guys who can handle the heat and the back braking work.

I would recommend you come down another 10k on your offer, just for a little added pad.

I think you would be impressed with the numbers .I also have a couple other projects in the fire  ..One being a 52 space mobile home park that I found for sale .. it is almost ready to start renting spaces .. the roads, water ( with pumping station ) electric, sewers, and zoning are all done ... it just needs parking pads and in my opinion some kind of Office / clubhouse.. maybe a Pool ?

Mice can get through a gap the width of a pencil , so all holes need to be filled and plugged with steel wire pads and/or filler.

Might do the Concrete pads this fall and underground electric and gates. 

Probably going to need to replace the carpet and pad to really get rid of the smell, & I'd run the ozone machine after the carpet and pad are removed before putting new flooring down.

., faster, cheaper, and easier to finance), converting a fixer SFR into a multi-unit, pad splitting (i.e., rent by the room), buying land and installing doublewides (then selling or renting out), etc.

In many cases with land you can have a road cut in, get a perc test, have a building pad built, install a well, etc... and increase the value and marketability!

These rentals are getting saturated big time and owners are not even braking even at this point.

Not to mention, often they may make unnecessary repairs, padding the account.