Some shopping venues that you should check out: Personally, I highly recommend Saigon Square (77-78 Nam Ky Khoi Nghia Street) which is the heaven for shopping with good prices. The shopping center is just a step away from Ben Thanh market. Yet, where to shop also depends on what you want to buy.
For example, for camping facilities, you could only find at Dan Sinh market. In terms of spa, Spa Tropic is great place that provides you the best mind-healing treatment. (http://www.spatropic.com/). Happy Ending Massage Yuan is also a good choice for travelers with tight budget (about $10-15 for food and body massage) and it is quite central ( on Le Thanh Tong street). Good luck !