Second-Best City to move for startups
brk: Boston meets all your criteria, except for cost of living.If you live in New Hampshire (like I do) you can commute to pretty much any place other than Boston proper, and reduce your COL significantly.  And even that, I worked in Cambridge for a while and it was manageable if I avoided peak rush hour times.The majority of the startup activity isn't IN Boston anyway, it's in the general beltway between 495 and 128.