Until 21st July we have made it possible to upgrade your version of Professional to Master Collection for the difference in price to what you have already paid*.
Simply enter your GameMaker: Studio Professional licence key into the Upgrade box in the Checkout and follow the on screen instructions to upgrade.
The amount that you have already paid for GameMaker: Studio Professional and any export modules will be deducted from the cost of Master Collection.
Lost your licence key? Visit https://www.yoyogames.com/support and use our licence recovery to get it back.
Go to the Checkout
*Please note that there is a minimum upgrade cost of $199.99 and all prices are shown ex. VAT.
**Unfortunately this offer is not available for users who have purchased on Steam.
There is also currently a sale for 40% off GameMaker: Studio Professional https://www.yoyogames.com/studio
Edited by rmanthorp, 17 July 2015 - 08:28 AM.