I always suggest folks try a set of metatarsal domes (or "buttons") which support the metatarsal "arch" and prevent the nerves in the ball of the foot getting pinched quite as badly. They only cost about $10 per set, and the shoe store should be able to show you where to put them on the sockliner or insole. (BEHIND the ball of the foot)

A set of domes/buttons is a lot cheaper than buying pair after pair of shoes, and can make a huge difference if you already have shoes that fit but still are getting numbness from compression at the met heads.