MIAMI—An exchange of five grams of cocaine for an undisclosed amount of cash "went off without a hitch" in Bayfront Park Monday night. "When I went to the park to buy some blow, I never expected anything bad to happen," said a 30-year-old drug buyer who identifed himself as John. "It didn't. I got some really good stuff, the guy didn't gyp me, and the whole thing only took, like, three minutes." Kold Kim, an area dealer, agreed with John, adding that the entire exchange was "cool."