I would be skeptical about the bad fuel pump. Rig may not be able to run, you can't road test it. An old $13K "bargain" rig cost us some 12K more in repairs to get it usable long ago before we knew what we were doing. Replacing roof AC units, water heaters, fridges, RV generators, converter chargers, fresh water pumps, and house batteries plus 6 correct type quality tires and brakes, awning and suspension can raise the cost of a "cheap" old tired shabby rig to where it exceeds cost of a much newer and overall better, safer, fully usable rig. You may not be able to buy discontinued 8.00 X 16.5 tires and need to replace wheels and use new radial tires. Water damage is very costly to have fixed.