Sellers mentioned the unit had an above ground oil tank that was removed and there is visible signs in the basement of plumbing for an oil tank.

I'm not sure Houston is the best area to buy right now with the oil prices where they are currently.

I can't tell how much oil is in the tank.

Also auction.com, Hubzu, Cook County Land Bank? 

These are usually “floating” sales persons, who one year are selling oil and gas programs, the next year time share resorts, and the third year used cars.  

This might sound crazy but in one bathroom that was a 36" shower pan I took sheets of 4 by 8 Hardie board with the wood grain and I installed it vertical and I sealed everything good with polyurethane caulk and I painted it with oil based paint....flawless...water just beads up and looks seamless...

They can cook, do laundry and have more space than a motel room has. 

@Eric Fung kilz origional oil based primer, seals the walls and you'll never smell it again, and blocks any stains from seeping thru, all my rehabs I always prime everything with kilz before I paint with top coats.

The only thing that I do inspection clauses on are Oil tanks, not that if they have one but if the remediation, if any, is over 50k.

She let the oil tank run dry, so we had to heat the basement to keep the pipes from freezing.