the easy answer is the yellow pages of any major city.
i'd look for one that has a garment district.
be really careful. it is easy to get a cheaper price, but usually that means an inferior product.
the problem will be shipping costs. find a good shipper first then find the wholesaler.
i am trying to ship a grandfather clock. the prices dock to dock range from 154 to 315 from 6 different shipping companies.
you will be looking at "ltl" loads.
perhaps ups and fed ex are good starts. my clock exceedes their volume standards.
they are cheap in primark
my daughter buys them and uses them to iron on her own images
and they wash great
depends on volume as to whether they would be cheaper wholesale, but i doubt
problem with primarks is you couldnt sell them on as they have the essentials trade mark printed onto them at the neck