Theres a ton of things you don't 'have' to do when building your motor. What does get done ofen separates the 'not bad' from the 'really good'. Like degreeing your cam, most likely the cam is good right out of the box, but the only to be 'sure' is to degree it.
You don't have to port and polish heads, deburr engine block
oil holes and a myriad of other 'details'. Like balancing 'everything'. That pressure plate is likely OK right out of the box for the average guy, turning average rpms.
It cost more to 'blue print and balance' an engine, all depends on where you draw the line how much more.