I got a PhD so I started a bit late but I do not regret spending my 20s as a grad student. At least when I started working, a PhD came in useful. I should note that this was a long time ago so my advice may be less relevant today. In general, my advice is to save as much as you can early in your career. Thanks to the power of compounding, $1000 saved in your twenties is worth a lot more than $1000 in your forties.