Any oil producing area will certainly notice the difference.

Are these places in the 'north' where you have oil heaters?

No oil changes, no belts, etc.

Kilz Original (oil-based) is good for previously-finished wood and heavily-stained walls.

Yes, there are plentiful deals.....and yes....even Detroit might one day be a goldmine for someone who buys the "right" $1,000 home and oil is discovered in the backyard.  

The first thing to find out is whether the existing paint is oil or latex.Unless when you said it had never been painted because the house is brand new.

As for oil tanks those can be costly and challenging if they are leaking as the soil conservation must get involved.

Like a oil town or Detroit with the automakers

It collects oils and stains like a sponge. 

If the smell is really bad and there's a chance of pet urine or other really strong odors, when you paint consider using a shellac (oil-based) primer first, at least on the floors (before re-carpeting) and up part of the walls.We bought our current home from someone who let their cats "go" wherever they wanted (it was nasty).