If you are looking for a complete backpacker outfit for your onward journey out on the islands, Khao San Road is a good place to start. Here you can buy tie-dyed hippie outfits, sunglasses and lots of other junk. The clothes are available in Western sizes, and tourists make up the large majority of shoppers, which is reflected by the assortment as well as the prices, which even after hard bargaining are significantly higher than on most other Bangkok markets.
One of the few things, which are cheaper on Khao San Rd. than at other tourist sites in Bangkok, is massage. If you do not mind rubbing shoulders with other sweaty backpackers on dirty mattresses directly on the floor, you can get a Thai massage for as little as 150THB an hour.
There are no BTS stations nearby and dishonest taxi drivers hang around in the area prey on tourists. They categorically refuse to switch on the meter, and demand a fixed price, often 10 times higher the metered price. To avoid this, take a walk a few blocks away and hail a tax from there.
Khao San Rd. first really comes alive in evening, where traffic is kept out of the area and the road is turned into one big market place. During the day, many stalls are closed.
• Khao San Road is one of the only areas in Bangkok, where you should be extra aware of pickpockets.
As you might have noticed, Khao San Road is not my favorite place in the city. For a nicer night market experience, I suggest that you visit Asiatique or JJ Green.