Stardoll has edited the starbazaar features, now it is open to everyone.
Now Non Superstars who have over 500 StarPoints and have verified their email address can buy items from the starbazaar.
However selling self-designed items in StarBazaar still remains a Superstar-only feature.
UPDATE : Stardoll "forgot" to mention the other changes they made - that is limiting starbazaar sales so that we can only sell 10 items per 24 hour.
(Credit to the Official Stardoll Blog and an anonymous comment)