Why spend $12 on panera when you can make a chicken breast sandwich for $4?
And it's worth noting that cooking for yourself doesn't always save time. After you consider preparation and cleanup, sometimes it consumes more.
It can also be stressful if you don't have a nice kitchen, or if you have to share your kitchen with others. Although probably one of the benefits of having founders living together is optimizing your kitchen.
You can always stick to the basics. Ramen takes ~10 minutes for boiling water and clean up. Chicken breast takes 2 minutes to season, 14 minutes to cook and clean. Tuna takes no effort right out of the can. Boil or steam vegetables for about 5 to 10 minutes. Rice or oatmeal are cheap sources for carbs.
With these ingredients, you can eat well for under $10 / day where I live (Providence, RI). Just make sure you invest in a good spice rack.
how much do you loose by not meeting new people?
I go out to talk to people while i work, most of our team does not, they are introverts, but I need to be the extrovert for the group, plus if these guys are bringing their wives or traveling back and forth, they can spend some of the food budget.