Anything Kate Middleton wears flies off the shelves.

Duchess of Cambridge has been credited with boosting the British economy by a staggering £1billion ($1.6 billion) – and there are entire websites devoted to her style.

But now it seems “the Kate Effect” is making real waves in the world of fashion, causing what is being dubbed “Kate-flation”.

Several of the pieces the princess in waiting has worn seem to have risen in price since they first made their debut in the duchess’s wardrobe.

Kate Middleton’s beloved LK Bennett “Sledge” shoe has gone up by £20 ($32), from £175 ($280) to £195 ($312) since she first wore them 18 months ago.

Kate Middleton’s beloved LK Bennett “Sledge” shoe has gone up by $32 since she first wore them 18 months ago

The “Natalie” clutch from the same High Street Store is also up £20 (to £160), and the blue Issa wrap dress made famous when she wore it for the announcement of her engagement in November 2011 has since risen by an astonishing £110 (from £385 to £495).

Whereas it was noted the UK inflation rate for food and clothing rose by 3.5% earlier this year, items with Kate Middleton stamp of approval have gone up by anything from a startling 12% to an eye-watering 28%.

So what’s behind this Kate-flation? Spokespeople for LK Bennett say their price rises are anything but a cynical way to exploit shoppers eager to recreate the Duchess’s stylish look.

Instead, they claim that rising costs have forced them to put up the prices of certain key items in their collections.

Soaring costs or not, one thing is certain: it will be the shoppers who are the real victims of Kate-flation.