People get scared if you look too much like a shark. 

I would suggest that when you go through the property you can look for condensation on any exposed water lines (sometimes you can see on the toilet tank or in the basement) if there is water condensation that seems to indicate there is a slow leak somewhere.You could also call the local water authority and ask them what an average bill is for a 2 bedroom, etc. and they may give you some good info.Good luck!

, spending well over two tanks of gas per week.

Underground heating oil tanks were sometimes used too.Keep doing your homework and know of all of the potential pitfalls.

The hardest parts I found were a) getting a bank to take me seriously and b) finding, assessing and making an offer before a larger shark came in and scooped up the property I was looking at.

:)It's exciting because I know I'm swimming with the Big Sharks.

When I max out my personal lines of credit, my credit score tanks.

New light fixtures, added a railing to stairs, new hot water tank, serviced the HVAC etc. 

There is clear evidence of oil tanks previously being present.

If so, septic tanks only last 30-40 yrs and if originally installed in 1991, could be nearing time to replace.