Can i buy the shop currency (microtransaction) with my steam balance?

Hi there,

You can indeed buy points packs or supporter packs with your Steam Wallet. You will need to be using the Steam client at the time, ensure you have Steam Overlay enabled and use the in game store. It should open up a window with which Steam Wallet should be a payment option. You will also need to have the funds ready and available in the wallet first.

Let us know if you have any troubles!