hmm, well that depends a lot on a few things


how much of the layout do you have done (ideas for the setup of the buttons)

how much concept art have you to start with, or will that be done by this artist

what type of detail are you looking for

what type of budget are you looking at

and finally, what time frame would the project need to be finished by


after these are answered, i can probably give you a pretty good estimate of what i could do for what price.