The price of the Branding Removal license is $199 and is the same for both activeCollab Small Biz and Corporate versions. You can purchase it from your activeCollab.com profile:

Once you have purchased the Branding Removal License, your license file on the website will be updated and will need to be updated in your activeCollab installation before it can be used. To do this, simply download the new license file from your www.activeCollab.com profile page and overwrite the existing license file in your /config folder with the new one. If you are not sure how to do that, feel free to contact us and we'll help you do this.

To verify that the Branding Removal license is successfully applied, please check System Information block on your Administration page which should display information showing that branding has been removed: