Bargain is not common in some countries, but in Vietnam it really is. In Vietnam, bargaining is always worthwhile. Yet, it is not always due to the fact that the local have a great deal of time and very little money. Bargaining is part of Vietnamese Culture as through bargaining people communicate with others, create and build up their relationship, not to mention a form of entertainment.
Indeed, some people bargain all the time because they are fond of price negotiating. Almost all foreigners find it hard to bargain although they already know the real price or the fact that they know the price prevents them from bargaining successfully. Except for some places that they offer products labeled with fixed prices, feel free to bargain almost anytime and anywhere.
To get better deal in Vietnam, you are supposed to take into consideration some bargaining tips as follows:
1 – It is vital to keep in mind that you will only be able to win the deal when you do it with grace and humour. So, just consider bargaining as a game or an entertaining activity and enjoy it.  As foreigners, it is not easy for you to use your words to persuade them to reduce their price as most of the locals do not speaking English well; therefore, your only remaining arm is your smile and your friendliness.  
2 – You should not bargain with the first person who approaches you due to some reasons. Firstly, the first salesman often quotes the highest price as they assume that you have no idea about the price and you would be “a chicken”. Secondly, going further, you are likely to be offered a better deal by others and you have chance to compare different prices.
3 – Walking away is a bargaining tool that you should not forget to use. If they call you back, do not let your pride get in the way of coming back. Otherwise, your above trick is useless. – Buying something in a third-world country does not necessarily mean that you are certainly ripped off as sometimes the given price is the real one.
4 – You are supposed to bargain in Vietnamese currency (VND) rather than in USD or your currency as in Vietnam, it is widely believed that who has dollars can afford to spend them.
5 – When you are bargaining, it is nothing wrong to tell lies as these lies do no harm at all. You could win salesmen’s heart and have their compassion by your lies, surly resulting in a better deal for you.
6 – It is necessary to carry small bills as you are acting like a poor, right?  Bargaining is a tradeoff between time and money, so if you are in a hurry, just forget it and be ready to pay for your desired products and services. Hope that you would definitely have fun with your bargaining.