Screen Protector vs. Cost of Replacing Crystal

I have an Apple Watch Sport with Aluminum body. I've tried a few different screen protectors and haven't been happy with any of them. I know it comes down to personal preference as to whether or not I use the screen protector... But does anyone know how much it costs to have the glass/crystal replaced if it gets chipped or cracked? If it's expensive, I'll deal with the screen protector. If it's reasonable, I might go without the screen protector. Thank you in advance for any insight.