I would say, u can rebuy once, that too cause u might have atleast got a read on players by that time and also u have an advantage that few players might come hard on u after u bust out once, which u can use to ur advantage if u are smart enough...
And if u get bust again, i suggest u to change the table rather than rebuy at the same table cause probably the other players have a better read on u than u on others...
Also if u get bust even in other table, then its time u log out of the tables and do some reading,watching and come back later...
Hope my opinion helps u.