The page describes each bottle as a 30-day supply, though other numbers on the page suggest a longer one.
On the page's own 30-day basis, three bottles cover three months, which is the $207 tier with free shipping.
Check the servings on your bottle: 60 mL at 0.60 mL a serving is 100 servings, which could last longer than 30 days. Remember the guarantee window is 60 days, so decide what you can fairly evaluate in that time.