Huancayo [1] is famous for its Sunday market on Huancavelica Street, where fresh food is sold alongside handicrafts on three blocks from Puno to Loreto. The best time to go is around 4–5 p.m., when vendors are packing up and are eager to bargain.
There are several small markets in Huancayo [1] that sell mostly tourist items—the best place is Casa de Artesano on the Plaza de Constitución (Real 495). However, you will receive better prices and have a memorable experience if you buy directly from the artists in their homes.
Villages around the Mantaro Valley [2] have markets where crafts are sold on different days of the week, including Wednesday in San Jerónimo de Tunán [3], Saturday in Chupaca, and Sunday in Concepción and Jauja [4].
Links:
[1] http://www.moon.com/destinations/peru/central-highlands/the-mantaro-valley/huancayo
[2] http://www.moon.com/destinations/peru/central-highlands/the-mantaro-valley
[3] http://www.moon.com/destinations/peru/central-highlands/the-mantaro-valley/san-jeronimo-de-tunan
[4] http://www.moon.com/destinations/peru/central-highlands/the-mantaro-valley/jauja-and-laguna-paca