Why do I need to use my credit card for purchase of avatar props?

Thank you, guys! I was successful in buying the avatar content using Xbox currency via the Xbox 360 console. I hope that the Xbox One is able to do this feature sometime soon.

Hey Rokutashi

Unfortunately, avatar items are one of the few things that you can only purchase using a valid credit/debit card or paypal. Sorry about this, but you won't be able to use xbox currency - perhaps you could use that towards a new game or DLC

If you have any other queries, please let me know.

You can purchase avatar items using currency on a 360 console. That store is set up differently than the store on the One and everywhere else.

You don't need to use both consoles connected in the same time. If you purchase an avatar item from the marketplace through your xbox 360 it will be available for your avatar in the xbox one console as well. For the moment there are a few free avatar items
(like the Mercy Wings Prop) you can download to try this out

To purchase avatar items you need a valid method of payment in your account (like a credit card) or you can use prepaid currency cards.

Avatar Props: Yesterday I purchased a really cool motorbike prop. It appears in the Avatar Marketplace and when customizing the Avatar, however it will not appear anywhere else. It cost 400 credits. Frankly, selling items that do not function as expected
(in this case, not at all) is fraud. See RICO Act. Two actions for XBOX: Either pull the dysfunctional prop(s) and refund the amount, or fix the issue. I definitely would prefer the latter. Thank you.