You can sell Switzerland iTunes physical on Cardest. Currently, Switzerland iTunes physical costs 320/$ on Cardvest.
You can check your iTunes gift card balance from your iPhone by following these steps.
1) Install the app store on your device
2) To access your user icon, tap the top right corner of the today tab.
3) Below your name, you will see your iTunes credit.
Click here to view other options on how to check your iTunes gift card balance.
Apple offers several digital services such as iTunes store and apple store via credits. iTunes gift cards are prepaid methods that let you purchase, download and watch music and movies. With iTunes gift cards, you can subscribe to Apple services such as Apple music.