Though josefinos mainly do their shopping at chain supermarkets, San José’s crowded indoor markets retain an old-world, authentic feel. This is the main market, lined with vendors hawking everything from spices and coffee beans to pura vida souvenir T-shirts. It's all super cheap, and likely made in China or Nicaragua (not the coffee beans, though).
In December Mercado Central sometimes has extended hours and is open on Sundays. While browsing, try an ice cream cone, or a quick ceviche at Poseidon.