It seems like a pretty speculative use. That much money would go a long way on a $20/month subscription, and the field is changing rapidly. Unless you’re an AI researcher, might as well wait a year or two and see what changes?

I suspect LLM performance will be a differentiator for Pro and newer Apple laptops in coming years.

If Apple releases on-device AI, this will be an effective way of getting people to upgrade like they used to, but haven't had to recently. For example, I bought Pro-level computers in my younger years, but now would only consider an MBA, mini, or iMac. But they could get me to go for a Pro if it were the only way to get more RAM for better AI performance. It will also likely shorten upgrade cycles since newer computers would have the latest and greatest performance. When I bought my M2 MBA years ago I suspected it would last me a long time. Now I'm not so sure since I don't have a ton of RAM.

5k for a computer with 128gb doesn’t seem like a great deal. You can get that much ddr5 today for like $400 sometimes less than that on sale.

What a waste. Build a 4090 desktop for that price, sheesh. Or spend the money renting spot 4090 instances whenever you need to via a MB air or whatever other laptop. And you'd probably still not end up spending the full amount.