The $5,000 relates to people to whom you have sold merchandise with the understanding that they are going to resell it, for example, if you sell $5,500 in merchandise to a customer who intends to take it and resell it online or at a flea market then you would report it is over $5,000 is sales.
The $600 refers to vendors or people to whom you pay money, for example, you paid commissions on merchandise you sold for a customer that totaled over $500 during the year.
