If you entirely removed the "lens" part that is cracked, would the image still be in focus? If so, then the cracked part is not a lens, but just a transparent dust cover or protector, and is not critical to focusing the image, so you can just remove it and replace it with anything transparent (and use silicone or adhesive to seal it up and keep the dirt/moisture out).
Look, here is what you can get for under $14 on ebay! Just might be worth the risk - if it doesn't work, then you wasted only $14 and can then proceed to spend the $700 or whatever to replace the entire camera:
Universal 8in1 Clip On Camera Lens Kit Fisheye +Wide Angle +Macro for Cell Phone | eBay
So you would just find which of those little circular covers is the closest match and use it to replace your cracked one. Normally I'd say replace your entire camera, but the price is, well, seems like an injustice against humanity to charge that much for a simple camera.