Expect a 1 dollar re-buy to be just like a 3000 player free-roll people will be playing trash and spending money in re-buys like crazy.
There are a couple of reasons for this, one is chip building some people have big bankrolls and will go all-in with any hand for the first half or more just to get a lot of chips on the table. Then near the last 10 minutes before the rebuy is over either tighten up and collect chips of just go all-in and hope to get lucky.
This is more common in the 3/5 and 10 dollar tourneys but it can happen in the 1 dollar tourneys as well. Usually in the 1 dollar tourneys people are just plain loose during re-buy hoping to just get lucky.
My best advice is set a limit, 2 to 4 re-buys plus add-on if you spend more than 6 bucks maybe your just in negative swing and shouldn't be playing. I've turned a few around after spending more than I should have but more often than not I do better if I just start out winning and don't have to stress.
During re-buy play tight, use POSITION, identify the gamblers if you hit the flop challenge them, play only premium
hands and try to see the flop cheap with small to medium pairs.
After re-buy until the next break survival is key, stay TIGHT, keep using position with premium hands and again spend time observing and taking notes on the other players and how they play. There's still a lot of donk play until the 2nd break.
After the 2nd break play your solid A-game try to stay at least averaged stacked move up if you can survival is still key.
If you can make it to the next break REAL POKER will be played in earnest. TAG in EP and LAG in LP, use your notes on who to
bluff and who to stay away from steal what blinds you can and if luck is with you you migjht make the final table.
Good luck.