You can buy the game and its DLCs directly from the Capitalism Lab Buy Page.
If you have a key you no longer use, or are looking for one at a potentially lower price, the developer believes this program is "true to the spirit of Capitalism". capitalism lab registration key free
A registration key, also known as a product key or activation key, is a unique code that is required to activate and use a software product, in this case, Capitalism Lab. The key is typically provided by the game developer or publisher and is used to verify that the user has purchased or obtained the game legitimately. You can buy the game and its DLCs