I should temporarily suspend Apple's payments for sales of my apps on AppStore. Other markets allow you to change the minimum amount to receive your payments, or suspend payments for a few months. Is there any way to do it on iTunes Connect as well?
You can adjust your app's price tier in iTunes Connect, including making it free and including setting start and end dates for the price tier change.
See these instructions from Apple for details of the steps to take for the app itself.
See these instructions from Apple for details of the steps to take for an in-app-purchase.