When you buy a license for Open Interest Version 4, you get: A license to use OpenInterest version 4 with no time limit Free bugfixes and version 4 upgrades Price reductions on future versions of OpenInterest Free product support (All prices below are in U.S. dollars.) An OpenInterest version 4 license costs $250. To upgrade from OpenInterest version 3 costs $80. To upgrade from OpenInterest version 2 costs $165. To upgrade from OpenInterest version 2 RealTime costs $65. Follow one of the links on this page to purchase a license. All transactions are completed through PayPal. If you prefer not to use PayPal, you can mail your personal check to us. Contact us via email for mailing information. Once you have completed the purchase, we will email your license key to you, usually within the same day.