I too agree on the Lunchables....the sodium and calorie content in those things is ridiculous.
Uncrustables? I'm not a crust fan, but that's easily solved by just not eating it. To buy a peanut butter sandwich with it pre-cut off, again is ridiculous.
With a lot of the other stuff, it's not just a convenience issue to have in the freezer when I want it, but also a "waste" issue.
Unless I am having company, for me to buy a whole bag of potatoes, (which I absolutely detest peeling), I end up throwing out what I didn't use, because we don't eat potatoes that often. It's easier for me to keep a bag or two of hashbrowns in the freezer, to use for potato soup, or the frozen mashed ones (OreIdas are good) that I zap in the microwave, and mash with butter and sour cream. They are there went I want them and haven't spoiled because I didn't use them in time. I buy the Bob Evans to jazz up and use in shepherd's pie, and they freeze well too.
Same thing with Texas toast. I don't use it very often, but I got really tired of throwing out half a loaf of fresh Italian or French bread. I always have Sister Shubert rolls in the freezer. I buy the big bags of them at Sam's and take out what I know we will eat at dinner and maybe a few extra for the next day.
I do think a lot of people buy the convenience foods for taking to work. Even as expensive as they are, they are still cheaper than fast food or from the machines at work. Where I work, they have a service with a kiosk that brings in "fresh deli" sandwiches and desserts. OMG, the prices on them!!! About 6 ounces of pudding or yogurt is $2.50-3.50! I went to get a half of a hoagie sandwich the other night and it was $4.75! I got a snack bag of Reese's cups instead. Damn things were $2.79.

I usually take baggies of snacks from home, but was working a 10 hr shift and wanted something nutritional. I figured chocolate and peanut butter covered enough food groups to qualify.
