If Teenage Engineering’s new OP-1 field is a bit rich for your blood - or, to put it another way, a bit expensive for your budget - then maybe you should try the LMN 3 on for size. This “DAW-in-a-box” has quickly been dubbed the “open-source OP-1” in some quarters, and could conceivably be had for a fraction of the price.
There is a catch, though: you’ll need to build the LMN 3 yourself, and it’s not simply a case of clicking a kit together like a Lego set. This is very much an advanced DIY build that will require you to source the parts (including a Raspberry Pi 4) and get your soldering iron out.
If you’re agreeable to that, you’ll find that the LMN 3 contains everything you need to start making music - a sampler, a synth, a sequencer, effects and a mixer. You can get a good overview of the machine in the video above, while a complete collection of repositories - including a build guide and parts list - can be downloaded via GitHub.