I had the same problem for years. I have large hands and found most grips were just too small. I tried the superstar ones, I liked the “girth” but they were too wide and the cartridges didn’t last long, before wearing down. I’ve had a set of Bontrager ones for four years and they’ve worn very well:
http://www.pedalon.co.uk/acatalog/bontrager-race-lite-lock-on-black-thick.html
Bontrager Race Lite Thick lock ons.
Not seen them cheaper anywhere else. Great, grippy compound and last well. I’ve rotated my old ones a couple of times where they’ve worn down at the pressure points but they’re still going on my commuter after four years!