economicaly feasible to rebuild powerhead?

I recently purchased a some stuff at a government surplus auction. One of the items in the lot was a 2005 Mercury outboard, 225 hp with trim attached. I am not a boat person so I took it to a local boat shop to have it checked out. The boat shop said the outboard is actually a Yamaha that was sold to the military as a Mercury. It is painted black, has Mercury decals but everything inside is really Yamaha. The shop said the computer recorded 1200 hours, and 800 are at idle. The engine has low to no compression. The shop said it is not cost effective to rebuild the power head and I should scrap it and sell the parts.
I have rebuilt many small block Chevy engines, and this is just a six cylinder engine. Are parts really so expensive that I can't rebuild this low hour engine to get it running so I can sell it?

I can't seem to find a complete rebuild kit for the power head like you would buy when rebuilding a car engine. Does Yamaha sell complete rebuild kits?

Re: economicaly feasible to rebuild powerhead?

alas no rebuild kits cause you dont know what you need.
could be some stuck valves.
until ya know what ya need its all a waste of time.
tear it down, see what failed and fix it.
the cost is in the labor.
to correctly assemble the crank and the crank case requires about 40 hours and new bolts for the block halves and connecting rods at final reassembly.
and then you only have the block assembled.