Some prices are fixed: bus fares are fixed; in supermarkets, restaurants and Western-style up-market shops, fixed prices are usually displayed, and that's what you pay. Elsewhere you are expected to bargain, and the object of the transaction is that both parties achieve satisfaction, and get some fun out of it. You can expect to beat them down to perhaps two thirds of the starting price on a single transaction, maybe more if you are buying several items. Prices of things like clothing are so low anyway that you can come home with plenty of bargains.

In fact, wherever there is bargaining, there are four guide prices. The lowest is for ordinary Thai people; next up the scale is for obviously well-heeled Thai; above this is the price for foreigners who speak the language, and the highest is reserved for you.

Tipping: maybe 10% in an up-market restaurant, but not roadside stalls. Meter taxis: round up to the nearest 10 baht. Hotel porters: maybe 10 baht for carrying your bags. A tip of 1 baht is a deliberate insult - don't do it!