... two prices of a custom tank, .125" aluminum, with 3 pairs alum fittings, pick-up, drops & shut-offs for the supplies, fill & vent, 1 access plate, 1 baffle ... both bids $700, one from a small shop fabricator in Florida who has done quite a bit of work for me in the past, the other from Luther's Welding in Bristol, RI, for who I've had excellent referrals. Triple M Plastics in Maine poly tank $1020. So actually 45% more in cost. I thought the costs would have been comparable. Price for the same "stock" tank from Florida Marine Tanks, same manufacturer of the one I have, $550, but if I replace the tank, will go the custom route.

Weight ... 65 lbs for aluminum and 80 for plastic = 20% more.

Cheers, John