I always have the grip on my 400D. It makes the camera more balance. I only remove the grip when I go travelling, that's the only time I appreciate the size and weight of 400D without the grip :bsmilie:
it will cost you about $150-$200 if i am not wrong... you can do a price comparison between CP and AP Funan... CP was selling 350D grip for $195 but i got mine over at AP for $180... so advice is do some price comparison before u buy it =D