From what I gather, it requires an Enterprise plan, which has no fixed price. Could just be a free part of the plan considering the price tag of an Enterprise plan.
CloudFlare claims there enterprise plans start at $5,000 USD a month, but this is not really true. Most customers who have a business plan and pay $200 a month negotiate deals for a lot less. Especially now that Akamai is dropping their pants to the mid market. You can essentially get on Akamai or Incapsula for less than what CloudFlare charges for their plans. This is what I did. I ended up with much better WAF services and less deviation on performance.
