The fuel will probably be fine. I had 5 year old diesel polished when I cleaned the tanks and it was AOK.
From the work program you laid out above, I don't think the capacity of the tank is the issue driving the costs -- it's everything else and $400 seems reasonable to me, if there's no access port. If there is one, $300 seems a bit steep given the size of the tank and the quantity of fuel involved.
If you can find the access port, you probably could do it yourself. Pump the fuel into a couple of 5 gal. fuel cans with a hand pump, then reach in and wipe down the bottom of the tank. When we did ours (it had been 7 years without a cleaning), we had about 1/4" of slimy goo on the bottom the tank. It came up easily using a couple rolls of paper towels. Close it back up, making sure to inspect the gaskets for damage; fill the tanks with fresh fuel and you're good to go.
Save the old fuel to use as a grease stripper when you service your winches, or see if you can find a mechanics shop that will take it. Some boat yards have tanks where used oil and other POL products can be disposed of in an eco-friendly manner.
It's not a hard job -- no rocket science involved provided there is an access port. If you don't have one, you'll have to decide what it's worth to have one put in. (Last minute idea: Ask your boat yard what they would charge to put in an access port. That will give you a guage on how reasonable the fuel polisher's fees are.)
From the work program you laid out above, I don't think the capacity of the tank is the issue driving the costs -- it's everything else and $400 seems reasonable to me, if there's no access port. If there is one, $300 seems a bit steep given the size of the tank and the quantity of fuel involved.
If you can find the access port, you probably could do it yourself. Pump the fuel into a couple of 5 gal. fuel cans with a hand pump, then reach in and wipe down the bottom of the tank. When we did ours (it had been 7 years without a cleaning), we had about 1/4" of slimy goo on the bottom the tank. It came up easily using a couple rolls of paper towels. Close it back up, making sure to inspect the gaskets for damage; fill the tanks with fresh fuel and you're good to go.
Save the old fuel to use as a grease stripper when you service your winches, or see if you can find a mechanics shop that will take it. Some boat yards have tanks where used oil and other POL products can be disposed of in an eco-friendly manner.
It's not a hard job -- no rocket science involved provided there is an access port. If you don't have one, you'll have to decide what it's worth to have one put in. (Last minute idea: Ask your boat yard what they would charge to put in an access port. That will give you a guage on how reasonable the fuel polisher's fees are.)