Brasilia is a planned city that was built in 5 years. One of the ideas was that each apartment quadra would be self-sufficient and supported by a commercial quadra. While most of this is still valid, some of the commercial quadras have evolved into specialty product quadras.
One of these is the Feira da Torre de TV on Eixo Monumental. Most shops are only open on the weekends and it is one of the few places where you can purchase some good, handcrafted souvenirs. You will also find plenty of stores that sell household, office, and outdoor furniture. They also make furniture to order.
And check out the food court area where you can find culinary specialties from every corner of Brazil.
Please be aware that not every merchant is honest. We had reports that people made some orders and were asked to pay the full amount in advance. Guess what, they never received them. DO NOT PAY THE FULL AMOUNT. Only a deposit and the rest when you get the gods.