If I save approximately the same amount cooking vs eating out, but it takes me the same additional amount of time to cook (again, assuming you don't enjoy that), then as my income grows the smaller the savings become as a percentage and the larger the monetary value of a given amount of my time becomes worth.
For instance, pre-made guacamole, if it's actually made entirely from real avocados, is more like $6 where I'm at if you want enough to feed 4 people multiple tacos each -- so twice the price you're quoting here.
My general food purchasing scheme is to attempt to only purchase the foods I can get at the best prices. If I am shopping and see a 10 pound bag of organic carrots for less than $5 I will buy it and have lots of carrots that week. For example: carrot salad, egg-rolls (carrot filling freezes well), soup, or stir-fry.
I can always buy tortillas for about 3-4 dollars for at least 6 dozen. I freeze them into one dozen stacks and defrost in the microwave until they can be teased apart and finished on a pan.
Some of the best deals I get are at Whole Foods. They often have very good sales on frozen foods. Otherwise I get foods at Costco, a local family market, and Trader Joe's. In the summer I occasionally go to a flea market to get specialty items and seasonal produce.
A jar of $1.80 pasta sauce around here is probably going to be more closely related to ketchup than real pasta sauce.
> tofu 1.5 / block
Hm. You clearly have much better food prices than I do in general, I guess.
One roommate now will only eat with us if we add up the cost of ingredients and charge him fairly. Many of our dinners cost only a couple dollars.
Pasta with marinara sauce and dinner rolls: 1.33 / pound pasta, 1.80 jar of sauce, rolls 0.13 each. Serves 3-4 people for $5. 15 minutes (limited by water heating).
Tacos with guacamole: $3 pre-made guacamole, tortillas 0.5 / 12 pieces, beans 1.20 / can, salsa $2 / half bottle, tofu 1.5 / block, cilantro 1 / bundle. rice ~$1. Serves 3-4 people for $10. 20 minutes (lots of tasks, have to cook tortillas).
I won't break it down, but I can do a nice sushi dinner: various rolls, cold tofu, inari, miso soup, for 3-4 people for about $15. 45 minutes (lots of tasks).
In any case I can feed three adults for about ten dollars and 2/3 of an hour of my time. Usually there are enough left-overs to make a nice lunch for myself.
I enjoy eating out, and do so about once a week. Before I got married I ate out a lot. I would spend about $900 per month just for myself. Now I make an effort to cook dinner 6 days a week and spend a total of about 800 per month on food for both of us.