“Buying diamonds off the street is a good business move.”Michael Derby, senior business consultant, Focus Business Management InstituteHenderson, Nev.BUY SMART: As long as you get a price that is lower—significantly lower—than wholesale, it is a good buy. Many times your wholesalers or other diamond suppliers are willing to purchase diamonds from you—especially bigger diamonds, as they are getting harder to source.TURN IT AROUND: We had one client who was offered the opportunity to purchase a seven-figure diamond. He asked [for] a few days to get financing. In that time, he found a wholesaler willing to purchase the diamond from him; got a short-term loan to cover the purchase; and ended up…profiting several hundred thousand dollars in about two weeks.PROFIT POINTS: If someone has an Internet mind-set, you can use a street buy to offer a lower-priced diamond but maintain a gr