I don't think it is the cost of the tank that is the problem, but the tough and tricky job of replacing it. On many boats I have seen and especially on mine, I would have to cut out pieces of the teak benches that support the cusions in the main salon which would not be an easy task. Replacing a fuel filter, belt, halyard, etc. takes about 5 minutes. Replacing the tank on my boat would take all day after the cutting, removing, installing new tank plus all hoses and vents, etc.