Man in the way the states are hurting for money, you better believe that they are looking to everywhere they can audit you. If after getting business lic. from state most retailers record your number and you do not pay tax. Raw goods in Fl. not taxed but put a sandwich together, tax has to be reported. Big brother Uncle Sam will have increase in audits for cash sale business. they have to.
Walmart, kroger, Publix go to customer service show a copy of tax Number they will give you a card or number. When purchasing goods give number or card before purchase, Non taxed.
 
Worked tax into sales price, kept count on items sold and worked up Monthly reports to states.