I may misunderstand the OP's concern, but - title aside - I don't think the re-gifting is what has her bothered. Rather, it's that the friend made a point of explaining that she buys special gifts at special store for special friends, who she then named - knowing that OP is not on the list and has never received a gift from that store from RGQ. The fact that the gifts RGQ has given OP are re-gifts is not the issue so much as the new-to-OP knowledge that RGQ makes a point of giving nicer gifts to others who are "special".
It's very much like going on and on about a big party for her friends in front of a friend that she didn't invite.
Only worse, because then she also labeled these people as her "special" friends.
I think I might suggest that you bring it up to her. "I have something to discuss with you that's sort of delicate, and kind of subtle."
Describe the incident in the store, and ask her if she remembers saying that.
And then say, "I have realized that my feelings were really hurt--and that I haven't been able to just slough it off. It's affecting how I feel about you, and I realized that it isn't fair to you to seethe in silence. That you deserve to know that this has affected our friendship.
"I realized, when you started listing off all your "special friends," that no one in my family has ever once received a 'purchased from scratch' present. We receive gift hampers that companies sent you at work--once I received back a present I had given you myself.
"We never really gave it that much thought--we just thought you didn't really 'do' presents. Until last Thursday, when you started listing all your "special friends" for whom you always buy expensive present from That Store. And I wasn't on the list. That's what really stung--not only to learn that you *can* be bothered to choose and spend money on present for other people, but also to learn that you consider those people to be special, and that you think it's important to show them that by carefully selecting presents just for them.
"Not only do I get castoffs that aren't even particularly suited for me, which makes me think you never spend any thought about me. But you clearly didn't think anything about telling me in a roundabout way that I'm not as special as those people.
"It really hurt. I've always thought of you as an extra special friend of mine, and it hurt to discover that our friendship is so incredibly one-sided. And that you apparently don't care if I know it."