During my stay in Ho Chi Minh City, I did a fair amount of shopping, for grocery, clothing and souvenirs. I found the experience to be exactly what I had anticipated: A bit disorienting and frustrating, but filled with interest, awe and a myriad of prices for indentical items.
The very first lesson I learned while in Vietnam was to wear a convincing poker face at all times. I am positive that the vendors can smell fear, and once they do, it is near impossible to negotiate a lower price. After learning the hard way, and almost being scammed into paying double for a banh mi sandwich, I had much better luck thereafter.
The trick is to appear unaffected and be prepared to walk away. The very instant you display unbridled joy at having discovered something wonderful, whether it be that perfect beach wrap or an amazing work of art, its price would have been raised exponentially without you even realizing it.
The food vendors walk around with baskets attached to a pole which is carried on their shoulder, or some push around small carts filled with everything imagineable. They are usually easy to bargain with, and I never felt ripped off.
Whether this is due to competition, or the fact that street food is not geared toward tourists, I found great value buying my meals this way. Large sandwiches cost me less than $1 USD, and the portions were decent and bursting with flavour.
Ben Thanh Market
This centralized shopping mecca in downtown Ho Chi Minh City is a complex maze to manouever. It is packed with merchants selling everything you would expect, and a few things you wouldn't. I bought several different fruits including dragon fruit and rambutan berries.
These fruits look somewhat bizarre on the outside, but are actually quite sweet and tasty. The prices being quoted varied dramatically, so all I can advise is to ask around for the best deal. Don't pay more that $2 to $3 unless it's a large portion you're receiving.
Further in the market, there are areas where local meals are being served. I had a bowl of Pho Bo, which is the equivalent of beef noodle soup and it was quite delicious. I paid approximately $1.50 for a large bowl accompanied by a small plate of fresh greens.
Sadly, I left my souvenir shopping until the very last minute, so I had to utilize the very touristy shops along Pham Ngu Lao street, and it wasn't my greatest shopping experience. The shops were not only unreasonably expensive at $3 for a keyring, but the vendors were rather unfriendly while others were borderline aggressive. Note: Souvenirs can be bought for far lower prices within the Ben Thanh Market.
Saigon may not be known for being a shopping destination, but if you need to buy anything while in the city, I recommend checking out the large markets first. The products will most likely be knock-offs, but the prices generally suit the quality.