Tā zài jiùhuòshìchǎng mǎile yī tái lǎoshì xiàngjī.
She bought a vintage camera at the second-hand market.
Tips
usage
Beijing's Panjiayuan (潘家园) is China's most famous 旧货市场, known for antiques, calligraphy, and curiosities. For a more general 'flea market' you'll also hear 跳蚤市场 (tiàozǎo shìchǎng), a calque of the English term.