How much does it cost to build an engine from scratch (like solid blocks of metal not parts)?

I want a 2 stroke diesel engine that gives 100-300 KW, the same reigon as say a 4l 4stroke diesel engine, the whole situation is completely hypothetical and would be for what the 2 stroke manufacturers call "marine" but none of them make engines of this size, theyre all 8 cylinder 2KPS upwards monstrosities that go to a size where the engine has stairwells built into them so I've assumed that buying one manufactured wouldn't be possible, however any information to the contrary would be interesting. I'm an engineer so im not atall worried about the design of it, in fact thats half the fun, but building it would be difficult as I posess little of the experience required for machiening parts, I would probably seriously consider paying a machinery shop to produce the parts for me. But what kind of costs does this sort of fabrication cost?