Well, I wish I knew, but I do know that engine builders are the most independent lot of characters I've ever worked with. They're impossible to hold to either a budget or a schedule, and they're worse than politicians when it comes to making pre-election promises, then failing to deliver. You can discuss and agree with them how the motor is going to be built, then you find out three months later they're doing something completely different. They don't answer email, and very few will even return phone calls. A few examples:
My 2JZ motor took two builders, 2.5 years and around $10K to build.
The 1UZ (long block only!) has taken 1.5 years and around $10K.
My V12 is now on its 2nd builder, and into the 2nd year, and I really don't expect it to be finished for another 1.5 years.
A fellow I know just had his BMW V12 built up and swapped into his 850Ci and his project took 4 years and more than $40K (but his had LOTS of exotic, one-off stuff inside, too.)
Sure if you throw enough money at these guys you can get things done faster. You can also get things done faster if you do most of the work yourself and only contract out the machining, but honestly, there aren't that many who have the time, patience and expertise to blueprint & build a motor themselves. My hat's certainly off to those who do.