If open source is a big deal for you I would look into Prusa, they have a great track record and a lot of other companies are using forked versions of their slicer. I have a Prusa MK3s and absolutely love it. I had a self sourced RepRap before this and compared to that it absolutely “just works”. I bought the multi color add on and was expecting it to be very finicky, but other than some initial filament loading issues (have to make sure the end of the filament goes to a point) I absolutely love it.
The Mk4 made up a lot of ground, but I agree they are a pricey option. Personally I was able to justify the price by the benefits of open source, if the company disappears tomorrow I’m confident the open source community could continue issuing firmware/slicer updates.