help wanted: strategy/guidelines for re-buys

[hyde]

I am sure this is the first time this question has been asked.......be kind.
I play almost exclusively single table SNG's. Occasionally I venture into a tourney. I usually rebuy right off in case I get all in with someone who has also rebought. I would prefer to get more than 1/2 his stack.
My first thought is that too many rebuys is not sound strategy, or everyone would be doing it...
I would appreciate hearing from someone who has thought this through further than I have.

hyde