3 to 5 sandbags will give you the taper and height needed. (probably, based on scotch consumption and tv speed) Sand bags allow you to adjust taper and height if you do not fill them more than 50-60%. You want to be able to make the incline proper for the clearance of the camper axles, frame and the tv hitch etc. if they are under-filled you can beat them into submission giving the proper incline. Some types of sand will be happier to stay in the laid down position if well wetted.
Value guaranteed to be worth price paid.
Tim