I have a friend that has been deported wants to come to USA to buy equipment to do business

A person who has been deported will generally be inadmissible.  It all depends on why he or she was deported.  You do not provide that information in your question, however, even where a person has been deported for a serious offense, he or she may be able to return to the US as a visitor only for limited purposes, such as buying equipment if he can convince the US consulate to recommend his application for a waiver to USCIS under Section 212(d)(3) of the Immigration and Nationality Act.  It can be a tricky process and while guarantees are not possible, it oftentimes works if put together properly.  If you are interested in looking into this further, you can call and schedule a consultation, in person or by telephone at (619) 291-1112.  Best regards,  Jan Joseph Bejar, Esq.