Depending on who you go to, your looking at about £300, the problem with fitting gearboxes on the side of the road is room and you will have to have the motor up of the floor to give you the clearence to get it off and out of the van (from underneath) we used to swap engines etc when we was a bit younger mainly mk1 escorts and 3 ltr capri's, we used to couple engine to gearbox when it was out of the car and then drop it in as one unit as this is a lot easier than trying to line up the clutch and wiggle the box on whilst lying under the car, end of the day it is a lot of arsing about if you can spend the money have someone do it for you, its a lot easier when the motor's on a ramp
C L