The G5 stone is the cheapest one to get the job done with. I've got a few hundred dollars in stones laying around that I use from 120 grit up to 1800 grit. If you wanted to go cheap you could try sandpaper on a flat, hard surface (marble counter top) from say 180 grit up to the finest wet sanding emory cloth that you can get your hands on but I doubt it's going to give a razor's edge.