Mark up on cameras is small and so you'll be lucky to get much knocked off and so we suggest asking for freebies like a spare memory card or a carry case. We bought a Nikon D7000 and a Nikkor 16-35mm lens and managed to get a free cleaning kit worth about $5...and were experienced bargainers so don't hold your breath.
Alternative PricesThe price of 42,900 Baht is for the body only. Adding lenses will increase the price quite a lot. Adding the 18-105 VR kit lens will take the price to 52,900 Baht.
Coming to Bangkok ?. Book your hotel through Agoda and save $$$ - see below