Owners of shops in Bambu Kuning are mostly sellers from West Sumatera. If you do not know how to --haggle over the price, you may get ripped off--paying too high for what you buy. Most sellers offer their clothes by doubling the normal price. If they say 100,000 IDR for a shirt, you should ask them to go come down to 50,000 IDR. That is what I hear from people who are used to shopping in Bambu Kuning market.
Bambu Kuning opens at 9 in the morning and closes at 5 in the afternoon. At night you can only buy foods or others at the shops that still open till late at night.