On a budget, weigh it — Café de Flore isn't cheap for what it is.
Café/light fare at tourist-premium prices (chocolat chaud ~€10–12)
Red banquettes and Art Deco mirrors where Sartre and de Beauvoir held court — and, crucially, the more design-and-fashion-leaning of the two great Saint-Germain rivals, where Les Deux Magots two doors down skews more literary-tourist. You're paying for the address and the terrace theater, but the famous chocolat chaud is the one item that's genuinely worth the premium.