I just did a passanger van last week with fourth row seating it was owned by a gymnastic center but it had 5 car seats in it so it looked more like a daycare. To make matters worse it had dog hair in it and to make it much worse it belonged to a friend of a friend and my partner had already quoted them 150.00 to 175.00.
I was going to descibe the whole ordeal but it was getting to be an extensive response so I'll just give you the overview. It had so many seats and so much carpet not to mention spills and dog hair(wich I didn't get all of due to them not being charged appropriatley). With my steam extractor and the four inch hand attatchment (I didn't buy the bigger attatchment because I've never needed it) I spent over four hours on the carpets and seats. Then I spent at least an hour on the rest of the interior plastic, windows, door steps, jambs ect. Then believe it or not I spent probably two hours on the exterior there's not much under the hood and I was too pissy to open the doghouse(interior engine compartment) but theres alot to wash and wax (don't even think about skipping the hood because it won't be any secret if they live or work in a multiple story building and the rain dosn't bead up on thier roof).
So after having about eight hours invested in the job and honestly I was not very impressed with the results I would have to say the minimum I would do a like job for is 400.00 wich would allow me ample time to do a final touch up and bring it up to my standards wich this one was not!
On the other hand I use to own a conversion van wich I always kept nice but would get pretty dirty after a camping trip or a couple weekend trips fishing, shooting, biking,ect. That I could cherry out in about five or six hours and I might charge a little less for the problem is these rigs are 3 times the size of a typical car or truck and are used much harder I would either keep dodging them or quote them a really high price and risk offending them the fact is I'd go broke doing these vehicles for 200.00 and I doubt the owners would understand why I charged that much!