Maybe I'm being too much of a purist because late model smart telescopes now allow you to grab the raw FITS files so the relative value of a fully open ecosystem is lower, but I'm trying to build towards the motivated teenager segment: someone who maybe has a Seestar or has seen one, and wants to have that experience, but wants to own it themselves and actually understand what's happening. I have the mechanics mostly working in Alt-Az mode, EQ mode is currently accomplished using a hinged plywood board fashioned into the world's shittiest polar alignment wedge, and now I'm working on figuring out how/where to source good enough optics. I have already learned a whack-ton designing the thing, and I hope that in the future the build will be interesting and informative enough for others to get a bunch of experience in Astrophotography for very little money.
You can buy the sensors used in a lot of these telescopes for <50USD on Aliexpress, the drive mechanics and electronics are ~80, and then all you should need (hopefully) is a cheapo Raspberry Pi 3 or equivalent, putting the total BOM at under 200 bucks. I'm hoping that by early next year I'll have something presentable and we can start building an open source ecosystem to compete with these very impressive but very heavily integrated instruments.