Have a selection screen where you can choose emblems or shaders and have all of them there. It isn't as though there would be much difficulty in determining whether you've had a particular item from the point that it was implemented (I can understand not being able to access ones we've already gotten rid of). A simple list on the server side could keep track of it with a simple yes/no. I'd be happy to pay 1000 glimmer each time I had to rebuy an emblem or shader. Granted, I don't think that items that you can purchase already, such as from the Speaker or Iron Banner should fall under that. As a side note, Petra should definitely have the emblems that you get through the course of the story available for sale. We got 5 or so for each character - it would be nice to know that I could get them back whenever I wanted.