Re: Dragon Age Inquisition Black Emporium Crafting Materials: Cannot Buy
@DragonLover64 Unfortunately, you are correct about the sound issue being common on the old gen consoles. Bioware stopped support for previous gen consoles around patch 9 (they really don't handle the game well and required more patching/support than the other platforms), and there are no more patches or content intended for the game on any platform. In short, there will not be a fix or patch, sorry.
Some people have found that saving and restarting the console after leaving the Black Emporium fixes the sound issue (just make sure to create a separate save before going to the Black Emporium in case this method doesn't fix the problem for you, some people have found that nothing they do fixes the issue, other than avoiding going there at all). Generally they suggest saving up before going so you can buy everything you want and never go back again, as it's a bit of a pain having to reset the console every time.
As for the other issue, I haven't come across that one before, and it does seem weird. Perhaps loading from before entering the Black Emporium and trying again will help? Have you checked to make sure no other stores are having this issue?
Sorry to be the bearer of bad news about the hopes of a patch (you are not the first hoping for patches for all the previous gen bugs, I'm afraid). Hopefully the reset thing at least helps with your sound issue.