I'm so happy I'm past the school supplies days!
[My youngest is in high school ... he gets to decide what supplies he needs, mostly. There's always 1-2 teachers with odd requests, but they're usually cheap, like 3 composition books.]
I ignored name brand on any lists, and bought things the same quality as the brand requested. Ticonderoga pencils? I bought cedar wood painted #2 pencils, often Staples brand. Elmer's glue sticks? Staples again. Avery college-ruled 3x5 cards? Sorry, they don't exist ... I bought cheap lined cards, and never got comments.
You see I mentioned Staples several times above? I don't know if they still do this, but when my kids were young, they would start back to school loss leaders, 3-4 items per week from early July on. I'd watch the sale flyers like a hawk, then go buy *only* the loss leaders each week. [I was doing the Mustachian thing of driving the marketing pros crazy by not also picking up overpriced stuff.] By the time school started around Labor Day, I had 90% of what was on the lists. I'd sometimes buy extras of things I knew they'd need in future years, like pocket folders or pencils.
A trick for middle school ... my daughter was generous with letting friends "borrow" her pencils. We came up with a trick — she kept a batch of loss leader cheap pencils with her, loaned those out, and kept the good ones for herself.
One final word ... remember, as parent, you are NOT the one in school. You aren't getting graded. The teacher isn't going to give your kid a C- because they didn't bring in the right brand of paper towels. As long as the supplies function well, the teachers are too busy to even notice brands.