I've always found Charlie Hoffman and Sons to be the most affordable. You can reach them at 732-513-2265. If you tell them you are my customer, I think you might even get a better price. I'm one of their preferred realtors!
Karen as mentioned there are many companies offering this service. The problem you will have is comparing apples to apples. Try to get quotes that break down for such variables as hauling contaminated soil if it is found as well as site restoration. Check to see if your home owners insurance will cover some or all. Older policies sometimes do. (they covered my $300,000 clean up) things have changed quite a bit with NJ now having companies do work with little over sight. I suggest not abandoning in place as this becomes a recurring issue when time to sell. Feel free to email me with questions. I have been down that road.
there are a number of companies specializing in this
Lombardo Environmental 201-796-339
ADS environmental 908-235-7916
ATS environmental 800-440-8265
Qualified Tank Services 908-245-0220
All well known but you should check them out and get estimates