In need of council having to do with Steam

So I literally just bought For Honor on Steam for full price on Tuesday, and I get home from work this morning to find it for nearly 20% off. Is there a case I can make to get back that difference? My brother bought the 100$ Gold Edition just two days prior to my purchase. He's going to be fuming. lol
Fortunately for him, he's young and free of the many bills he'll soon face, but just being reimbursed the 10$ would absolutely make my day.