There are two easy ways to buy Citrix XenServer:

• XenServer Solution Provider Partners
  • XenServer Gold Certified and Certified Solution Partners can offer Citrix XenServer in all configurations, support volume purchases, and offer evaluation and implementation support services
    
• XenServer Online Store
  • Use the Online Store to purchase single copies of Citrix XenServer Enterprise Edition and Standard Edition 2 Socket Licenses Only, without evaluation or implementation support