All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
We ask Allah to bless you and help you show dutifulness towards your parents, and we advise you to be keen on doing whatever helps you earn the pleasure of your mother; for the mother is sincerely eager to preserve the best interests of her child. So you should buy decent clothes that are acceptable by the Sharia and please your mother at the same time.
Allah knows best.