I think skins and stuff are free on PC except for pets. Pets are extra paid as they are DLCs, not just a regular buddy. It's also only like £2, go onto the menu, there should be a little dollar icon. Click that, and choose the pet you want, click the buy button. Reload the game and go into a lobby, customize, go to pets and select it, you know the deal. At least it gives two pets in a bundle and you can get all of them with the 'buy all' button.