Remember when you calculate the cost of cooking that you have to add in the time spent grocery shopping, cooking, washing dishes, the cost of the electricity, gas, and water consumed, the time and cost of disposing of the trash, wear and tear on appliances, etc.
Dining out is essentially outsourcing these tasks.
Time spent on grocery shopping, washing dishes, etc. are only opportunity costs, they only cost money if you were to otherwise use that specific time generating income.
For someone working on a startup in his free time, there are only opportunity costs! If it costs $10 extra per day to dine out, that's $3650 a year. If it saves an hour a day which can be used for working on the startup, that's 365 hours, or the equivalent of 45 business days at a full time job.
Is cooking really such a hateful activity? I kind of enjoy it, sometimes. It can be relaxing .. sort of like programming with edible code. And chicks dig guys who can cook (not to mention that guys obviously dig girls who can cook).
Which means: cooking is probably the most effective way to use programming skills for romance :)
Dining out is essentially outsourcing these tasks.