You have not researched enough to see the whole picture. A 450HP aluminum small block with a Mr. Goodwrench Factory Warranty, one of Eric's (AEAuto) adapter plates and clutch and starter, and a Porsche/Audi 01X transaxle will be well under $10,000. Just a set of headers for a V-12 could easily be over $10,000 and/or a multi year project. That is only one example. You are going to have similar issues with the water pump, air conditioner, wiring, and so on. A nice set of ceramic headers for the small block is $99. But as I keep saying, if you have cubic money, go for it and continue the V-12 pursuit.