I live in San Francisco. I can go to any of the nearby markets in Chinatown and buy more produce than I could possibly eat in a day for under $10. I like to cook soup-based dishes which would be a pain to take to an office, but a sandwich and a piece of fruit is pretty doable. I believe my great grandfather did that for decades.

Honestly, I think going with what old people ate while you were a kid will be easier on the pocketbook and the health.