Ask HN: Best hardware investment for learning ML in 2023?

Hi HN'ers, I'm a new grad / software engineer and have decided to learn ML and experiment with some models. I wanted to buy a PC for coding and ML experiments. I want to try running larger models and perhaps experiment with new architectures too. I am also very interested in RL. (I am aware that I cannot compete with companies like OpenAI in terms of compute power but I still have a hope of doing something new in terms of application or architecture).

What would you consider the best investment for a begginer? Would a M2 Mac be a good choice? My main concern is that my initial investment should be extensible, so I could add more compute/GPUs later if required.