Other companies are rushing to get a piece of the market, too. Nearly 27,000 patients are in Florida's medical-marijuana registry, with the potential for tens of thousands more. The going rate for a visit, which can take 30 to 45 minutes, is $200 to $300. Health insurers won't pick up the tab because cannabis is not approved by the Food and Drug Administration or legal under federal law, said Cathryn Donaldson, a spokeswoman for the trade group America's Health Insurance Plans.