This is an old thread i know but i can bighly recommend two areas near Chatuchak market. Both are on the edge of the modern market. Easy to access via Mo Chit BTS Line. Just walk clockwise round massive market Saturday & Sunday. I regulaly pick up Thai Orders and even found a British RVM EIIR in a GVIR box obviously for GVIR Funeral to Thai delegation. This weekend i bought a Full Sash set of Order of Thai Crown of Son of recipient for £90 (3700 baht ) he was happy and so was i !! There is an occasional Coin & Banknote fair with some medals but they know how to price things !!! Good Hunting
