It's most unusual, the one-day dress sale that Marta Koehne plots for next week at her Hot Couture vintage clothing store in Santa Rosa's Railroad Square.

A reality-TV crew will shoot it, for one thing. Then there's this:

Though Koehne will place on sale a truckload of 540 used dance and party dresses, those 540 make up just 1 percent of the total number of dresses owned by the Southern California couple that is parting with them.

Paul Brockmann grew up in Germany and he was still living there when he came to savor the way a fine dress moves on a woman as she dances. He began to buy dresses — and figures that over the past half-century he acquired 55,000 of them.

His wife, Margot, danced in a good many of them. But over time she had a heck of a time finding a place to hang them. So her husband rented warehouse space.

Now in their 70s and living in the Southern California town of Lomita, the Brockmanns have decided the time has come to let the dresses go.

Word of their big sell-off reached Koehne and she arranged for the delivery of 540 dresses to her shop on Thursday, Nov. 21.

She expects to start selling at 2. It promises to be quite the scene.