Price tag was different from the cashier price

So i bought this Pokemon card in Den Den town, Osaka. The price tag says it costs 21,780 yen with tax. But when i went to pay, they were charging me 24,000 yen. I was able to reduce it to 22,000 due to tax free option. I only noticed once i saw the receipt after.

Anyone know why this was the case? Pretty sure they dont up charge to tourists?

Here is the photo of the card: https://imgur.com/a/sZyRvK8