Listen up, label lovers! What if we told you there's a way to get your hands on designer duds…at a price that'll have you calling the fashion police?

It's time for a high-fashion party. And we're all invited!

Kim Nelson is a self-proclaimed shop-a-holic. "It's not that I purchase something every day, but I do go online and shop around everyday," she admitted.

So when she received an invitation to a "members only" shopping Web site…she could hardly wait to start spending.

"I feel like it's a privilege. I feel like it's this exclusive shopping world."

An invitation like Kim's is the key to sites like Ideeli, Rue-la-la, and Gilt.Com… where designer duds are sold at bargain basement prices. It's everything from clothes, to shoes, to jewelry.

Rachel Shechtman is a member of the Council for Fashion Designers of America. She explained how the stuff can be sold so cheaply. "Whether it's past season merchandise, or excess inventory, it's a very discreet way for them to sell goods online without it appearing on Google searches."

It's also a way for designers to control when and where their brands are available. The Council for Fashion Designers of America says…invitation only sites first popped up in Paris.

"There were lots of copycats in Europe and abroad," Shechtman explained. "And since then, over the past year, there's been more models like that that have appeared and popped up in the United States."

Here's how it works. Members get an email announcing the opening of a "designer boutique." Pieces are up for grabs for only one or a few days at a time… or until they're sold out.

Think of it as a "flash sale"...Where you can snag a steal for 70% off or more!

"I think it can become addicting!" Kim admitted to us.

The sites grow via word of mouth. Take Gilt.com, for example. Once you receive an invitation…you can invite your friends to join you.

Founder Alexis Maybank told us it's a great way to grow. "So if we have a member in L.A., she'll know much better who else out of her friend group might be interested in Gilt Groupe."

The site features everything from diamonds to dresses, Maybank told us. "We were selling sunglasses that retailed for about $300 at Barneys on our site for about $98."

But to grab the goods, you have to click fast! "In our Diane Von Furstenberg sale, we were selling 8 dresses a second!"

Ben Fischman with Ruelala has seen a similar response. "Within that first hour, many of our styles have already sold out. We're doing our best to make sure we can get as much inventory on the site as possible," he shared.

Kim recently struck gold on a site when she found a dress that was sold out in stores. "I looked through and they had my size, and I was very excited and purchased it right away," she told us happily.

You must be invited or sponsored to join the sites. Gilt.com gave us a special 'key' for viewers. Head to gilt.com. Then enter your email address.

Ideeli is also offering a similar deal just for TMJ4 viewers! Go to www.ideeli.com/in/media?mi=tmj4 for more information.