Im looking at 2 motors at the moment and can"t decide which is the better buy. 1st is a 40hp tohatsu twin cylender 99 model $2,500. The other is a 40hp Mariner(yamaha)93 model $2,000. The Tohatsu has had piston replaced due to an overheating incident with a plastic bag but looks like new. Mariner is in very good condition also but has a fiew scraches. Are these motors correctly priced? which is better buy? Also is there any publication with second hand valuations of various motors? Should the Tohatsu be as good as before with only 1 piston replaced (standard size) Many thanks again...