Bangkok is one of world cheapy shopping center. Clothes, key chains, sandals and other souvenirs are sold in low price–depends on how you can bargain. Yepp, bargain is the only way if you don’t wanna be tricked by the vendor who set the price higher than it should be. And to support this skill, learning some local vocabulary could be beneficial. Who knows that the psychical binding which is held because they appreciate our effort to speak in their language, they will give extra discount 
I found this useful video to learn some shopping vocabulary easily. You can write some of them on a piece of paper or memorize them if you want. “Phang Phai!!” or “Too expensive!!” is my magical mantra when bargaining, how about you?
