Depending on your district’s policies and the demographic of the parents, you may want to consider letting parents know about your last minute needs. Some parents enjoying donating items to their child’s classroom. In my school, we have a Curriculum Night one evening during the first full week of school. It’s a great time to delineate expectations and establish lines of communication. In a prominent place, I display sticky notes, each labeled with a classroom need (zippered plastic bags, more index cards, etc.). Anything you know you’ll run out of before year’s end can be on this wish list. When you do your class presentation, you can explain what needs the sticky notes represent, along with your reassurance that it’s fine if they don’t take one.
Given the amount of money you’ve probably already spent on your classroom, this can idea keep you from spending even more.