depends on level of tourney, payoff
I've only done the
freerolls, with add-on, and rebuy. If the money is no big deal to you, it might be worth it, early in tourney, when its usually cheaper to add-on, re-buy. Essentially, buying a decent beginning stack, without the risk of your stack.
Later in the tourney, it's usually a loser, risk/reward: spend a dollar to re-buy, and the ITM is less thna a buck. Re-buy is usually less than the average stack, usually one or two more bets. It would only be worth it, if the payout for ITM is way higher than the rebuy.
Different tourneys have diff payouts, diff how much rebuy/add-on costs.
You can analyze it better yourself, when you see the actual costs/rewards.