Additional related data point: I tried to buy Battle.net currency in-store with trade credit yesterday and a similar error popped up. I thought I bought some recently but could be misremembering.
Noticed we typically keep things close to our chest around these parts, but I've seen the Sony INZONE H9 headset marked down to $90.
Didn't get outstanding reviews at its $300 price tag, but may be a different story with a 70 percent discount.