User has activated and is using his/her version of Dial IT with ACT! Version 2005. Upon upgrading to ACT! Version 2006, the license for ACT! 2005 becomes invalid. The User may then re-register the license, whereas the renewal cost is fixed at 30% of the valid addon purchase price at the time of license renewal.
 

User has activated and is using his/her version of Dial IT with ACT! Version 2005. Upon upgrading to ACT! Version 2007, the license for ACT! 2005 becomes invalid. The User may then re-register the license, whereas the renewal cost is fixed at 45% of the valid addon purchase price at the time of license renewal.
 

In summary:

When ACT! is upgraded by one version, the fee for license renewal for the addon is 30% of the current price.

When ACT! is upgraded by two versions, the fee for license renewal for the addon is 45% of the current price.

When ACT! is upgraded by three versions, the fee for license renewal for the addon is 60% of the current price.