Fuel costs are only part of the equation . Consider the 3 year , Non Declining warranty of the Etec.Not to mention the 3 year service interval. Also , from an ecological standpoint , they are cleaner running ( no nasty clouds of 2 stroke fumes ).
Any new engine would be a good investment , but I have a leaning towards the Etec ( I own one ) . Yes , they do cost more , but you get a lot of engine for your money. Call Craig at Huetts , he will definately get you the right engine for your application .
Ross