There are two ways to get the gold dress. You can either buy it from Persephone's shop or you can trade for it in the clubhouse.
Here's how to be able to buy clothes from Persephone: You have to actually purchase a piece of Kinzstyle clothing for your pet. It's usually available at the same stores that sell Webkinz. The clothing will come with a code that will place a shopping bag in your dock. Once you drag the bag into your room, the shop will open. There are different shopping options each time you open the shop, and you do not have to purchase the first time you open the bag. Just keep trying until the gold dress is available! If I remember correctly, it's pretty expensive - around 9,000 KC.
Good luck!
Here's how to be able to buy clothes from Persephone: You have to actually purchase a piece of Kinzstyle clothing for your pet. It's usually available at the same stores that sell Webkinz. The clothing will come with a code that will place a shopping bag in your dock. Once you drag the bag into your room, the shop will open. There are different shopping options each time you open the shop, and you do not have to purchase the first time you open the bag. Just keep trying until the gold dress is available! If I remember correctly, it's pretty expensive - around 9,000 KC.
Good luck!