Depends on where you are, where you're ordering from. Horses being sold by color isn't always good because horses tend to change colors to their environment. I have purchased all of my horses in Canada, and prices have ranged from 79 - 149 EACH. Then if you are having them flown to you, you must also pay the freight (about 60 bux with tax) on top of your order.
I have 13 horses right now, all different variations of yellow, with 2 exceptions...one is orange and one is mottled black/white.
Where are you thinking of purchasing from? What kind of horses are they and are they captive bred? I know of a great place that I got mine from, got to hand pick them too (on an out of town trip) and that was the best experience.