If you want to experience an aunthentic and traditional Thai way of buying and selling goods, you should visit the Floating Market at Damnoen Saduak, Ratchaburi Province, about 85kms from Bangkok.
To go to the market you need to ride a motor boat. Along the way you will already see several houses, including those traditional ones. You will know when you arrived the market when you see the river crowded with hundreds of vendors floating in their small rowing boats selling fruits, vegetables, souvenir items, etc.
Since this is a tourist attaction, you should learn how to haggle to get a good price. My
mother asked for a colorful hat and fan combined, the initial offer was higher but she got it half the price
.
Here are some of my pixs.

colorful items along
the riverside |

fully loaded w/
fruits for sale |

me,mom and sis |

fruits there are
cheap and sweet:) |
Baby
woah, i love that idea. floating market.. one of a kind shopping experience..it sure looks fun seaciel..