I'd look around...that seems a bit on the high side. It shouldn't take a competent shop more than three hours max to do all four corners, and if they're quoting you at an hourly rate you'd be looking at about $133/hour. Unless they're including alignment in with that price, in which case it would be very reasonable.
I'd shop around, or even do it yourself...its not hard. It took my friend and I about three hours to do the SVT suspension kit on my ZX3, and that's counting us being idiots and not loosening the strut tower bolts before putting the car up on the lift and taking the struts out of the front spindles.