MK4S

You can sell it, there is probably some customer base with mk3 and mk4 that may consider it for right price. I believe for various reasons enclosure for mk4 was really dead end. The Biggest issue is to volume you have to heat up, location of the printed part on the bottom due to printer construction

I have a Prusa MK2 that I can turn on and print like new, if I wanted. It has 28k hours and I've only replaced belts once, and fans due to bearings wearing out. I have three MK3s with more than 15k hours each, one near 20k. Again, only a few fans, one extruder because of my own dumb mistake. My MK4S

I've had a Core One upgraded from MK4s for 4 months. The only problems from your list I've experienced are the gantry squaring, and prior to the fixes Prusa made there were minor VFAs in some prints, now gone. There's definitely an assembly problem if your nextruder main plate wore out in 2 months.

I use the auto rewinder adapter for (un)original Prusa drybox and I find it totally reliable. It also fits on top of my Lack enclosure. OP, imho, this decision comes down to $$ and time. If I needed another printer now, is probably go with another MK4S w/mmu3 if only for the convenience of having mu

I actually have 5 mk3s+. Upgrading all of them to mk4, mk4s or later to Core One would put a big hole in my pocket. So I just upgraded two of the mk3s+ to mk4, both to mk4s afterward and one to CoreOne two weeks ago. However, I upgraded only two mk3s I had in stock configuration. Two of the other mk

Just 400 more and you got an mk4s while i have and use an mk3s+ (still not upgraded, the kit 3.5 waits on the shelf) i would not buy a new one. The next generation with the new more powerful buddy board and the new hotend is a big step forward. The mk3s+ is a long living workhorse. I would call one

A secure way with granted success at the end of the process would be buying a Prusa Mk4s+ Kit and assemble it. The build manuals offline and online are awesome i have no doubt that you will success. Not the cheapest but you need no printer to build one. After the build you have a workhorse printer a