I also rented a minivan from Dollar at BWI for a week, as they were running a $199 per week special...cheaper than anyone else. Didn't ask for a specific type, got a regular Caravan. The wait at the counter was awful, and they were automatically giving a extra 10% discount because it was taking 30-40 minutes. In my experience, Dollar tries to get any extras it can to make up for lower rates so a $10 "upcharge" does not surprise me...but it probably was creative revenue enhancement by the agent.