My other worry about the mac is how unupgradable it is. Again not sure how fruitful it is - in my (probably fantasy land) view if I can setup a rig and then keep updating components as needed - it might last me a good 5 years say for 20k over that period? Or is that too hopeful?

So for 20K over 5 years or 4k per year - it comes to about 400 a month (ish). The equivalent of 2 MAX pro subscriptions. Let us be honest - right now with these limits running more than 1 in parallel is going to be forbidden.

if I can run 2 claude level models (assuming the DS and Qwens are there) then I am already breaking even but without having to participating in training with all my codebases (and I assume I can actually unlock something new in the process of being free).

I'm curious how much lower quality we're talking about here. Most of the work I ever get an LLM to do is glue-code, or trivial features. I'd expect some fine-tuned Codestral type model with well focused tasks could achieve good performance locally. I don't really need worlds-leading-expert quality models to code up a hamburger menu in a React app & set the background-color to #A1D1C1.