However they are in the long run likely to be expensive since they require their supplies (which are reportedly good, but expensive)

They’re literally not expensive at all. You can get good quality PLA for as little as $13/KG if you buy in bulk (4 rolls or more) and all their replacement parts are dirt cheap. Bambu didnt take over because of great marketing, they took over because they build a great product at a great price as well as thinking about every little creature comfort one might want and including those too. I do think they’re going down the same road as Apple, but so will every other successful company, so you might as well enjoy it while it lasts.

If you want something to tinker and expirament with, you should build something like a Voron and not a premade commercial product.