I ran into the same problem a few years ago. I was told that I would be looking at around a thousand dollars or more. Chisel bit files are way cheaper than that! I love the binefits of square filed chain, so I practiced with a file and I hand file my chains. They stay sharp a while as long as you keep it out of dirty wood and the ground. Hehe. My advice to you is, if you sharpen a lot of chain, a regular grinder is great. If you get a good grinder you will be very happy with it. If you have the time and patience, doing it by hand isn't that bad. I mainly do it because it is relaxing to me. But to each his own!