Comment by bluescrn

Last time I looked, the MK3->MK4 upgrade kit is basically the same price as a complete MK4 kit (very little can be reused. New electronics, motors, extruder)

The upgrade kits are definitely a good thing, going from MK3 to MK3S to MK3.5S was a worthwhile upgrade path and has prolonged the useful life of the printer. But they have their limits.

(And with 3D printing going more mainstream, there's a large segment of the market that has no interest in building printers from kits or stripping down printer to install upgrades - even though some of us find that quite enjoyable)