The only way to be sure is to contact the company and ask for a list of their approved wholesalers. 99.99% of the time, there won't be any.
Most of the wholesalers are hawking poor quality fakes.
for new mens clothing/ t-shirts try wholesalelinked.com Wholesale Linked is us based. they have $50 minimum and free shipping ove $300. i bought them before and never had an issue. Let me if it works for you.