Hi jkatz - I am a sales manager for Vates America Corp and I apologize for any confusion but 'complete feature set' is referring to XOA. We list XOSTOR, XOPROXY, and Airgap Support all as 'optional' because they are add-ons and incur additional costs. One of my team members or I will be happy to answer any questions you have and discuss the various costs of our add-on offerings. We can be reached at sales@vates.tech and we'll look forward to hearing from you.