Bing: Cost going up after time as active member?

I searched this reddit, but I didn't see it mentioned anywhere. My husband recently got his own bing to earn an Xbox Gold GC and I happened to notice his prices for gift cards were what I remembered from when I first started using bing. I've been using it off and on for about a year now and for the same GC's with my "gold" discount, it's consistently 200 bing points more expensive than it is for his. Does anyone have any insight into this?