Do not get ripped off just because you don’t know the value of the currency. If one person charges you 3000 Dong for a handful of pineapple and another tries to charge you 120,000 Dong for the same stuff, you know you’re being ripped off. But if the first person you encounter tries to charge you 120,000 Dong… that’s when it helps to know that there are 30,000 to the pound. Four quid for a handful of fruit is definitely way off.