I don't think usualsuspect was particularly mean, by MN standards.
I sympathise with the OP. In a similar vein, I remember the Poor Kids tv show and subsequent thread. At the time, I thought (but didn't post), how can they not afford to get their kids' hair cut for that long that the kids are being mocked over it? Now I can't afford to get my kids' hair cut for school starting next week. And that is despite MIL paying for 5 x school shoes (trainers, football boots, ordinary school shoes).
And the OP is in a horrible situation re the husband. It must hurt every time she is scrimping on stuff because her ex-husband doesn't seem to care about his kids anymore. And I agree about coming to despise Pasta.
But on the other hand, a lot (if not most) people on MN are ordinary and shop at places like Asda, and don't see it as some kind of terrible thing. So I can see usualsuspect's point.