Over charged for building Permits?

[Carroll Lee]

I plan to develop new construction on land in DC that has never been improved. So it has no existing foundations no utilities hook ups.   So to get to the point where I can get a building permit will require some extra plans.  I received an estimate for 3 items. "Zoning Plat and site plan", "Erosion and sediment control plan", and a "footing and foundation plan with details".  The total for all three is $6,000.  

Does anyone have any experance with getting these documents prepared?  Is this a fair price or are they over charging?