Depends a lot on where you live...
Training usually includes the board, so on average around here (PA) you can pay anywhere from $600 - $1100 for training. Of course there are extremes at both ends of the really good and really inexperienced trainers, so make sure you check everyone out.
If you are only looking to have her broke (I assume 30 or 60 days training? W/T/C and basic stearing undersaddle)I would look for someone who specifically breaks horses in your desired discipline. Sending to a top not jumper trainer to simply have your horse learn to w/t/c is expensive and you arent really utilizing the trainers expertise. There are tons of trainers that specialize in starting the young horse, and rates are usually a little more reasonable.
"The white horse moved like a dancer, which is not surprising: a horse is a beautiful animal, but it is perhaps most remarkable because it moves as if it always hears music."