Depends.....

Personally I enjoy building engines (good therapy especially when you open the box and find out they sent you the wrong main bearings )

When I was doing it for customers, I built the hi performance engines, but for a bread and butter daily driver or slightly warmed over street motors (cam, header, intake type stuff) there was no way I could match the factory crate engine price or warranty.

Just depends on what you want to do and how much you want to spend.