Not all "wholesalers" are created equal. You want to avoid middlemen who simply mark up prices they found elsewhere. Cosmetix Club
This document allows you to buy products tax-free, as the sales tax will eventually be collected from the end consumer.
Before most reputable wholesalers will even show you their price lists, you need to prove you are a legitimate business.
Most U.S. vendors require an Employer Identification Number (EIN) and a general business license.
How to Buy Wholesale Makeup: A Step-by-Step Guide for Your Business