How do I give different customer groups different prices and products?

Group the buyers. Then price, promo and gift them as one. Every customer can belong to groups: the varsity roster, one account's employees, a chapter of members. A group gets its own pricing, its own promotions, its own campaigns, its own redemption codes. The order history stays on the person; the rules ride on the group. Add a new hire to the group and they inherit everything in one step. One person can sit in several groups, so the coach who's also a parent gets the coach price on the polo and the parent promotion on spirit wear.

What it used to cost you: A spreadsheet of who gets what, kept by the one person who knew the team.

The feature is called Customer groups. It runs on the same rails as everything else here: one catalog, one price list, one cockpit, your name on the front.