Just because she's royalty doesn't mean she's lost her sense ... fashion or common.

Savvy shopper that she is, Duchess Kate Middleton took advantage of some end-of-season sales and hit London's Chelsea neighborhood this week in search of good deals.

Was her endeavor successful? What did she find?

An onlooker says the royal, who just turned 30 earlier this month, shopped at the store Anonymous by Ross+Bute, trying on some new pieces from the spring and summer collection, including a pink cardigan and boots.

Sshe decided on a marked-down Jewel Collar V-Neck Top, a grey, form-fitting merino lightweight sweater accented with a bejeweled necklace attached along the neckline.

It was on sale for 84.50 GBP, $129 USD (from 169 GBP, $259 USD).

While checking out with her only purchase, the Duchess paused and admired a clutch bag, but decided not to buy it. Her visit to the shop lasted about 20 minutes.

"She was really polite, well-spoken and mentioned she would be coming back in the future," an onlooker adds, not that anyone would be surprised by that.

The last time Kate Middleton was photographed out in public was when she walked the red carpet with her husband, Prince William, at the War Horse premiere.

Even her 30th birthday, which was the day after, was spent in a low-key manner, when she held an intimate dinner with family and friends in private quarters.

She has also been seen walking on the beach in Wales with her new puppy!