8 tests on how many acres?

maybe instead of looking at the cost per sample, maybe you need to look at the cost per acre....

I think Agboy makes a good point - if those guys need to drive 1/2 hour (or more) to get to your farm, before they start pulling samples, maybe that is where some of that cost comes in.

Maybe it is a good idea for you to pull your own samples, as you suggested.  Nothing wrong with that.