If you de-trim and and make sure the car is spotless inside , ie not loads of dust about then you could get the car done , assuming esc cos , for about £200
If you leave them to de-trim and hoover and clean then you'd be looking at £300 i'd say .
My mate does it and was going to do my mondy est for just the price of the film if i did the de-trim , so help them and they'll help you .