If you order online there's no proof of being a student required. Just click through the Education Store link on the left side of the home page.
Just so you know, they do randomly verify it by calling and asking you to fax proof of enrollment or employment. And since they have your credit card number, and your agreement saying you qualify or will pay the difference, they have both the ability and the contractual right to charge the difference if you can't or won't provide the proof. Probably don't do it often, but I have had to fax proof twice in the last 15 years or so.