You can get Arkansas stones for $25 and up to a few hundred. It all depends on the quality and grit. Best Sharpening Stones produce quality Arkansas stones. I have a few.

Japanese water stones are a little more pricy, but I haven't found anything that matches their fine grit performance ... except for the new Shapton Glass Stones. I recently got a 8000 grit and am impressed.

I would like to get a 30,000 (that is not a typo) for the final touches on my razors. (yes Skunk. You were correct) I will get a Shapton Glass 30,000 when I find it for under $300