Credit: Claiborne Swanson Frank/BFA

Who isn't looking to make a knockout impression on the holiday party circuit this season? But buying a new cocktail-ready dress for each fête is not only expensive, but also totally time-consuming. Enter Armarium, a new online service with a corresponding pop-up shop in the St. Regis hotel in New York City that allows customers to borrow designer fashion and accessory pieces for a fraction of their retail price.

“Our woman is someone who is very fashion-minded and wants to be able to wear something special and highly curated every time she steps out,” says co-founder Trisha Gregory, a former public relations director at Ferragamo, who started the service with designer Alexandra Lind Rose. Thus far, Armarium has partnered with 20 designers for the launch, including Nina Ricci, Anthony Vaccarello, and Alessandra Rich. "It’s a mix of established and emerging brands, but each piece is unique and statement in its own way," says Gregory, referring to an Etro paisley jumpsuit and Prabal Gurung fox fur.

If similarities to Rent the Runway come to mind, Gregory insists Armarium’s offering is much more selective. “It’s about 15% of the retail price to borrow ready-to-wear pieces that cost anywhere from $2,000 to $15,000,” she says. "We know what it's like if you can’t get your hands on look 44; this is for the fashion insider who knows what she wants and really wants to wow."

The Armarium online service won't be available until spring 2016, but the pop-up shop is open starting today until Dec. 24.