Anything you buy there you can get somewhere else cheaper, but since you have a gift certificate you can't be thinking that way. Just get a really nice brush or a stand and enjoy it, don't think about the price.
+1. I'm getting a $40 gc for Father's Day, which will be spent on one of their traditional shaves, probably the Royal. It promises to be a once-in-a-lifetime experience (for whatever that's worth), but it's not something that I'd do just for the heck of it. Daughter wants me to use it on something extravagant for myself.I'd buy a few soaps, a DE and would probably spring for one of their professional shaves and a haircut.