When looking at a rebuy, consider it as being a deepstacked tourney that begins when the rebuy period ends. In other words, you will need a decent-sized stack to be able to play deepstacked poker with the rest of them. What may appear to some as being an hour long donkfest actually has a means behind the madness (in many cases).
When playing a rebuy you will usually be on the same table with the same players during the rebuy period. Any rebuys made while on that table will be chips that are still in play for you to try to get ahold of,.. goal being to try to acquire a stack of around 5500+ during the rebuy.
Sure some play rebuys with a one-bullet approach but realistically it's not the best approach for playing a rebuy tournament. Can you imagine if you were playing a rebuy and got stuck on a table where all the players only
had intentions of playing it with the one-bullet approach (no initial rebuys, and no rebuys during the rebuy period). It'd suck and you'd no doubt be in terrible shape for the rest of the tourney.
I've got some friends who are regulars in the rebuy tourneys and they say they'll often rebuy 5 to 10 times. They also do quite well in them.
I wasn't overly educated about playing rebuys (still not) but have read some excellent articles about them and have watched a pretty decent 4-part training video where the commentator/player takes the viewer thru all stages of a rebuy tournament. It was quite enlightening... not just listening to what was going thru his mind but also what he was predicting in his opponents. It's changed my view on rebuys ever since.