Piwik is free to download, customize, and use. Please visit Piwik.org to download it.
Piwik PRO are professional services from the creators of Piwik.org, providing cloud hosting and analytics consultancy for users of Piwik.
Piwik Cloud monthly plans start from $65 (incl. 300 000 actions per month). Complete list of plans can be found on Piwik PRO website: https://piwik.pro/cloud#pricing
Piwik Enterprise involves different plans. To find out which plan will best suit your needs please get in touch: https://piwik.pro/contact