I think everyone is still overcharging because supply is almost non existent. I don't know how that store managed to get all those cards, here in Norway supply has been near zero this year. Expected dates for when 1080 Ti cards arrive at the stores is typically one month ahead, and when that date is reached another month has been added already. No one is buying cards because there are none, and (large online) stores overcharge on the maybe 20 cards they receive every 2-3 months as a result.
I don't quite understand what the problem is, locally high end supply seems to be a few percent of what's normal. I've heard of some memory supply issues, but is it really this low? I'd expect to hear more about it in the media if it really was as bad as it looks. Demand isn't a problem when stores have been completely out of cards for four months, yet there aren't any cards expected to the stores in the near future.