It's cheaper via Sport Direct, and it's not like he's not going to get the money if you buy it from the NUFC shop, is it? Infact buying it from Sports Direct would probs mean that he gets less money.
It's not Ashley though is it ffs, neither company is his own personal wallet.
Buy it at Sports direct, the money goes into sports directs accounts. Buy it from the club, NUFCs account benefit.