OT-Renting vans(mini/full-size) in/near DC

[agnes!]

I'll try to make this short(lol)
Well, I am a Girl Scout Troop Leader for some Junior Girl Scouts. We live in Northern Virginia & they voted to go to Hershey Park for our end-of-year trip. The problem is, we have committed to go on June 3, when they have the day off from school. Only about 3 kids out of all 14 can't go that day...but now we're not sure we can get enough (seating space in) vehicles for transportation.
*So*...has anybody here ever rented a van, either a mini-van *or* a full-size van in the DC area and gotten a good deal? If you have, I need details...company, codes, tips, etc. These kids have all had a great year & I want to make it possible for us to take this trip, even if I have to rent a van myself. I don't have to necessarily rent from an airport location.
It's funny, I can rent a car for a WDW trip in a flash, but I'm having trouble wading through all the various car rental companies up here...

thanks,
agnes!

 

[agnes!]

Just trying a ((bump)), hoping that *someone* has been able to rent a van(mini or otherwise) & pay a reasonable price for it. So far the cheapest price I have been able to find has been around $100...ack .

thanks,
agnes!