Home sale prices in the city of Austin skyrocketed to a record median of $536,000 in October, up from about $441,250 a year ago. And they have more than doubled since 2011, when the median sales price was $216,000, according to the Austin Board of REALTORS, a trade group. Rentals, too, have surged, with the average cost of an 864-square-foot apartment now $1,600.

“Austin is the worst-kept secret,” said Job Hammond, a secretary-treasurer with the board.

With the University of Texas flagship campus, gentle rolling hills and a vibrant music scene, Austin has long been an attractive place to call home. But surging prices have created a brewing housing crisis that is reshaping the city of nearly 1 million people, and pushing mostly low-income Black and Latino residents like Mr. Nuñez away from cultural centers, transportation hubs, grocery stores and other amenities that come with urban living, activists said.