Q: Apple Store contracts charges, are they always obvious?

Do you know if there are ever charges applied to just updating applications at the App Store?

That is the issue actually, because on some of the updates (for example currently for Numbers and Garage Band updates) one is asked to give their Apple ID and to read a contract and agree that 'charges may apply' - so it is confusing to a new person whether to install any of the updates that ask for this.  I contact support people as your link suggests if you don't have this information. Thanks. 

This information is certainly for beginners (who can find it takes a bit of time to get it if you don't already have the experience with a Mac).......Clicking the App Store icon in the dock (or under the Apple decal in the horizontal menu at the top of the page) brings you to the "Updates" (and right next to this on that menu is the word "Purchased" - which lists all of the apps you have downloaded or installed on your Mac -- even if they were free! -- which is a different concept for the heading 'purchased', you will admit.)  This is what was confusing me: "Purchased" doesn't mean there was a cost attached in this context.