Where can I buy cheap women's business clothing in Bangkok, Thailand?

I am mainly interested in a few pant and skirt suits. I am a size 0 in Victoria Secret pants and skirts. I am also interested in nice blouses and non typical clothing. What sizes should I be looking for? I don't want to spend more than $200. Also how do I get the vendors to sell me cheap authentic or great handbag knock offs? Where would be the best place to purchase them? I don't want to spend more than $15 per handbag.