Greetings to All of you!

I would like to use Piwigo to show and to sell items. The price of the items (one item = one photo) is different for different users.
So, for all items there are let's say 5 different prices. Users see the prices only if they are registered and logged in. User A sees the first price, B sees the second, C the third, and so on.
Non-registered users see no prices, however, they see the photos and desciption of the items.

The desciption of the items is the same for all users, and the photo is the same, as well.

How may I show to all users the appropriate price?

Thanks,

Tamas