From a design/manufacturing standpoint it simply makes no economic sense to design a machine to prototype with only 70% of the parts implemented and then attempt to shoehorn in the remaining 30% of the intended build to another model based on the existing design.

Logic dictates that it is far more practical to have the machine built to 100% of the planned specifications first with finalised build costings attached to each individual assembly and then simply remove certain assemblies/parts to cut back on the BOM in order to bring it in line with the lower price point model.