The cost of the DAR is on you ($500 here) instead of the FAA having to carry an employee to get us in the air.
Technically, MIDOs are responsible for all "original" airworthiness inspections.
In the past, they have generally allowed FSDOs to do experimental aircraft, but within the last few years, some MIDOs have withdrawn this procedure.
Many of them are overloaded now days and refer applicants to DARs.
You could point out that your tax dollars have already paid them to do the inspection. 'Course if you do, they'll probably tell you that they will be out to do it two weeks from the next 6th Tuesday.
Maybe ask them who in their department pays the DAR, since you really have already paid them to do the inspection.
Just sayin'....
Charlie