There is the Sovol SV07 for about 300€-ish. It comes with Klipper and should check all your boxes. I bought the SV06 Plus two months ago it works OK. You have to tighten all the screws and actually read the manual, but that’s it. If you want a guaranteed problem free OOTB experience, you have to buy Prusa (top quality control and software) or Bambulab (not really hackable but runs well) for 600-800€.

I was in a similar position recently, but also valued OpenSource (see meel being here ;) )

I went with the Prusa Mini+ semi assembled kit.
it’s been chugging through filament for a few months.

I bought an Artillery 3d Genius, after owning an Ender 3 for 4 years. It has worked flawlessly out of the box, while I needed to tinker with the Ender endlessly.

There is a 3d printing discord, that has an often updated flow chart. Assuming you dont want resin, the choice is mostly based on how big you want to print + budget:

• <200m^3: Kingroon KP3S ($170) or Prusa mini+ ($460)
• <300m^3: Artillery Hornet ($170), Sovol SV06 ($300), Prusa MK3S ($800-$1100)
• 300m^3+: Sovol SV03 ($400), Ultimaker S3 ($5k)

Prusa is top of the line for open source and very much falls into “works out of the box”. The other bed-slinger style printers like Ender are cheap but tend to have issues and are a money-sink for upgrades to get them working (lots of mods there). If you’re into hacking and modding stuff though, look into Voron printers. I’m not sure if any of the Voron versions fall into your budget, but you can buy a kit or do open-source. They’re self-built, extremely fast, customizable, and really meant for the people in the printing community who like to program and mod things.