Extra large backpack, rolling backpack or maybe just get a dolly

Strap for the zip binder. Wear like a messenger bag.

Ugh, poor little one, I wish schools would have some consideration for the amount of stuff that the kids have to schlepp around. I can highly recommend Mountain Equipment Co-op's backpacks. They have a kid's section for book bags but I'd go to the http://www.mec.ca/product/5032-795/mec-book-bag/. I bought mine in 2005 and it's been to college and across Canada a few times and still looks new. It has a reflector strip and an internal laptop sleeve in case she needs one in a few years and lots of internal and external pockets. I just love mine. They ship to the USA.

Have you considered a rolling suitcase? A quick perusal of Target's website showed options less than $60. Your local thrift shop would probably have them for even less. They come in a wide variety of styles to suit any fashion conscious (or unconscious) student.

I'm an erstwhile trumpet player and I'd switch her to a fabric http://www.musiciansfriend.com/trumpet-gig-bags for sure, unless she is a total klutz. Those hard cases can be really heavy and unwieldy.

A bit over budget, but the http://www.llbean.com/llb/shop/64778?feat=816-CL1&page=turbo-transit-pack is HUGE. It's also the last back pack you will need to buy due to LLBean's http://www.llbean.com/customerService/aboutLLBean/guarantee.html?nav=p2b-fs. She puts either her textbooks or her jacket on the "bottom level" and lunch + remaining school stuff on the "top level." (Note: this backpack is often comically huge on middle schoolers). Backpacks designed for swimming and/or hiking are often on the larger size as well. While her future school may forbid rolling backpacks, it may not mandate the massive binder. From personal experience, I suggest that if you are learning towards a rolling backpack, double check that she would actually use it first. I'm assuming that the lunchbag your daughter has is smallest size possible and not super bulky. (More http://www.promotional-items-inc.com/catalog/lunch_bag-economy_colors.html http://www.kidperfectpieces.com/Kids-Lunchbox-Bright-Orange-Insulated-School-Lunch-Bag-WildKin_p_754.html than http://www.dhgate.com/store/product/8l-picnic-lunch-bag-insulated-cooler-bag/155251415.html shape). In addition, your daughter will have more flexibility if she uses a trumpet case that is a shoulder bag instead of a backpack.

Have you considered a shopping trolley? http://www.rolser.com/web/index.php/en/products/shopping-carts are great. And if your daughter doesn't like it, hey you now have a shopping trolley. They are very useful.

Sorry I missed your price restriction. They have knock-off Rolsers for much less at ethnic malls.

Also, this year I was mindful to buy backpacks with external cording for jacket capture. Could you add simething like http://edcforums.com/threads/bungee-cords-for-backpacks.90070/ to her bag to stuff her jacket & spent lunch bag in?

Thanks everyone--the trumpet case can't be changed and she's tried the shoulder strap on the binder case but she still carries a separate backpack with books, lunch and jacket--too much. After looking at the options, she likes the giant Jansport backpack that MadameM suggested. The rolling backpacks are probably too bulky and heavy for her to lug up two flights of stairs. I think the giant backpack is the winner!