Is this Kate Middleton's most expensive dress yet?

Kate arrived at a fundraising gala at the National Portrait Gallery in London without Prince William. Photo / Getty

If anyone is going to absolutely nail a $11,000 dress, it's Kate Middleton, the Duchess of Cambridge.

She sported a sleeved lace frock by London-based designer Temperley to a fundraising gala at the National Portrait Gallery in London.

She teamed the floor-length gown with a pair of $14,000 ruby and citrine earrings by Kiki McDonough, along with a gold Wilbur & Gussie clutch and metallic Jimmy Choo heels.

Kate wore a sleeved lace frock by London-based designer Temperley. Photo / Getty

Her total look came to over $32,000. Photo / Getty

The designer outfit - which had a collective price-tag of over $32,000 - was a far cry from the Duchess' tendency to wear more affordable high street brands like Whistles and Reiss.

Kate flew solo without her husband, Prince William, for the exclusive party also attended by British "It" girl Alexa Chung and model and presenter Donna Air, who is dating Kate's younger brother James Middleton.

Gone Girl star Rosamund Pike and Arizona Muse were also at the gala.

Chung, 33, wore a polka dot off-the-shoulder gown by Spanish label Loewe.

She took her father, Philip, as her date in lieu of her boyfriend, Big Little Lies hunk Alexander Skarsgard.

The couple are rarely pictured together in public despite having dated for nearly two years.

New York-based Chung - a model, writer, designer and former MTV presenter - is set to launch her own self-titled "contemporary-priced" line, Alexachung, in May.