Happened to me for ni no kuni. I F5'd until it said 50 bucks, then went to my order page and it said 72.
Then I tried again just now by deleting and readding instead, and My ORders says it's 54 bucks.
Actually it's looking like you're right, at least in my experience. Refreshes haven't been working --- it keeps showing up as $72 in orders, and now removing from cart and re-adding totally still works. Just got Ni No Kuni II that way.