$8,000 - $10000 buys a LOT of fuel.
3mpg vs. 2.3mpg
Atlantis, Veatch, Hydrographer Canyons aren't out of range now
here's some stats of a 29ft oceanmaster powered by twin 2.0L mercs . . . You can find a set of these for 2 - 3K and they'll give you similar fuel economy to the Yamaha 130's.