The dealer quoted me $478.02 for fuel pump for my Chevrolet Astro. Is this reasonable?

they have to drop the gas tank to get to the fuel pump. The fuel pump is in the top of the gas tank, if you run your gas low in the tank, for example just by ten or twenty dollars worth at a time, the fuel pump does not have enough gas in the tank to cool it. The fuel is supposed to help the pump run cool, I keep my tank full of chevron super unleaded wth techron this keeps the fuel system clean , I fill up when I get to half and keep my tank more full then empty. I use good quality gas so the fuel that goes through the pump and filter is always clean. Poor quality gas has water and other chemicals to boost octane, and running on E all the time puts a lot of crap in the fuel pump and filter. which will plug up sooner or later.A full tank and the techron in the gas helps keep deposits from forming, and keep the fuel injectors clean and the filter lasts a lot longer as well.