Plus, laundromats suffer from environmental issues as well that can reduce the value of the property. 

So my question is besides legal, title and environmental inspection, what other contingencies would you require, and if we're "all in" on the deal, is there a danger to agreeing to a high DD fee to try to win the deal?

You could be on the hook for the cost of environmental cleanup.You need legal representation from an attorney with experience in gas stations.

@Jack Tucker - A few things about gas stations that you need to keep in mindLenders will require that a Phase 1 and\or 2 be performed to ensure there are no environmental issues.  

You won't be able to get a permit and if you don't have a permit you are going to get cited and lose in the environmental "court"

You will need a Phase I Environmental Assessment.

If it's a mechanic shop and you're looking to change the use you're going to have to spend some money and you could even run into environmental issues.

An environmental study?

Industrial on 14 acres the cost of environmental remediation alone could exceed your purchase price.

We backed out of the deal due to environmental concerns regarding contaminated soil from a UST that was taken out back in 1987.