If you live in Seattle and you find items are rung up for the wrong price, I highly recommend reporting it to the city. I did this once and was shocked that they promptly sent someone out to check the store and issue a citation. The inspector who emailed me was very polite and professional as well. It's rare to have something like this taken seriously and to have the enforcement properly funded.
Unfortunately I don't remember which form I filled out but I believe it was this one
https://www.seattle.gov/your-rights-as-a-customer/file-a-com...