Most school districts usually have a list of recommended instruments. This list will often have three or four different brands and models that the district approves for beginning band. These instruments aren’t chosen at random, and the district does not get anything for recommending certain instruments.
It is in your best interest to choose instruments off of that list, if one is available. Be very careful about the incredible deals you can find online. Rest asssured, all of the instruments I recommend are of good quality. They are horns that I would purchase myself. I feel confidant that any brand and model of instrument recommended by a band director will be available at the merchants I recommend and at a better price than pretty much anywhere else.