one more item. . .
The task you are requesting requires a consultant to use a drilling crew (step 1) and then engineering compilation and recommendations with a license. Many engineering firms will not let the drilling crew loose to work alone during step 1. Sure, the drillers will make hole, but who's controlling where they drill, how they handle the samples and the recording of the whole slew of "fugetive" information (i.e., drilling rates, changes in auger-flight cuttings, changes in lithology noted by drilling action, etc.)? Nobody! In my former consulting practice, I'd NEVER price out a project to let the drill crew loose on a project. I ALWAYS had a field geologist working with the rig (i.e., $95.00/hr). Your requested scope of work does not imply that this is a project requirement. So, some are likely pricing with free-range drillers and others are pricing for drilling inspection.
Also, consider the report. Do you expect a site plan showing boring locations and any other field observations (i.e., piles of stuff that's seen on the property)? Or, are you happy with no figure and just some longitudes and latitudes for boring locations?
If this job's in Virginia, heck I'll do a few hand augers and give you a report for a real low price. May not be what you are expecting though. It may just suffice to the local jurisdiction though. . .
f-d
¡papá gordo ain’t no madre flaca!