If you play R+A (rebuy + addon) tournaments, then your first goal should always be to make it to the add-on period, and you should be willing to rebuy as many times, as this requires. For this reason you also need a larger bankroll. Whereas a 220$ bankroll might be enough for a normal 2,2$ tournament, if its a 2,2$ R+A, like for instance those on 888 Poker, you want to have something more like 550$ to play these. That might sound like a bad deal, but its not, because you are also going to be competing for the same kind of prices, like you would in a 5,5$ tournament.
If you are talking about tournaments without add-ons, then rebuy is usually called reenter, and it basically just mean, you play the same tournament one more time. 888 Poker call it "second chance rebuy". Playing the same tournament twice is no more "money sink" or gambling than playing two different tournaments. So yes you can do this, if you still want to play the tournament. It wont effect your long term results at all, unless you make mistakes like playing, when you are tilted from losing. And it also does not effect the required bankroll. You can still play regular 2,2$ tournaments with a 220$ bankroll, even if you sometimes decide to reenter after an early bust.