408 shortblock pricing
I would say $3000 if you are building similarly to blue print.
Being a smaller entity you could work with each individual buyer to select cam. Charge extra for the cam service.
Offerings for LA blocks would be great. Blue Print is Magnum only.
A service for folks who may have their own LA or Magnum block. I've recently used Fastenal for shipping and it's not that expensive. Some folks might have a date correct or original block they might want a basic build on and don't want to do a Magnum block.
Basically, follow Blue Print's lead but offer a more focus on the individual customer's need based on a standard rotating assembly.
Parts availability will be your biggest roadblock..