GNC amplified wheybolic extreme 60 alternative?

I'm 110 lbs (female) 25 y/o. I'm sailing, kayaking, and kickboxing 5 days a week (all three everyday Mon-Fri). I bought this stuff to help with my muscle strength and growth. I'm not liking the $59.99 price tag though, so is there another protein at GNC that is comparable with a low cost that you would recommend? (I would would ask the sales people, but that's how I needed up with this.)