I don’t know how the average person weighs different quotes from different shops to rebuild an engine for them- there are as many definitions of “rebuild” and “overhaul” out there as there are belly buttons.
How far a shop will actually go towards blueprinting/measuring an engine to actually determine whether everything is within specs will certainly affect the final cost of the rebuild, due to the man hours involved to take the time to check everything that should be checked, and to correct everything that should be corrected.
I think it comes down to how invested you are in the outcome, and/or how much of a gambling man you are. I think that some owners know they won’t be keeping their vehicle for long, so paying more for a rebuild doesn’t make sense to them, and some of those who plan to keep their vehicle, don’t mind rolling the dice on a cheaper engine rebuild, since the engine likely won’t see much service anyway.
Then you have those who are obsessed with doing things the right way, regardless of cost. And all the people who are somewhere in between the gamblers and the obsessive….. Plus, every owner has a different situation with each vehicle they own- so some of it will be situational.
Such a subjective process, selecting a shop and a price for a rebuild! And even after considering all of that, you can never be sure that you will get what you paid for, in the end…. as all it takes is a single distraction when it comes time for the kid in the shop to torque the compression fitting on that oil feed line from the oil pump, or when tightening a rod bolt. I guess we should just be happy that it isn’t a Boeing 737 that will fall out of the sky when maintenance checklists aren’t followed.
My wife has a ‘63 GMC pickup that needed lots of engine work on the 350 someone had swapped into it. I had no history on the engine, and she needed something reliable to drive. After weighing out the costs of machine work, and how much of my time I had to give up (this was about 5 years ago), I settled on buying a base 350 GM factory NEW long-block crate engine, delivered to my door for $1600. Made in GM plant in Mexico, 1 year warranty. I had no idea what to expect from that engine, but it has run like a champ from day one. So far, so good.