Why don't try to buy it in Armani Exchange?
If price is the problem, try ARIZONA in JC Penney. I am positive they have it. It is cheaper than H & M! If you happen to have smaller body frame, also try AMAZON in the kids department.
You have to try bigger size in boys dept though. Small in men translates to L in boys for that fitting type of shirt. Don't worry they carry all the way to XXL in boys!
Trust me, I work as a personal shopper as my part time gig in the weekend; so I know
Good luck!