It’s rather late in the day to start making plans for either of these highly popular destinations—in what is probably the busiest week of the year! That said, I’d advise the Andamans over Bali, if for no other reason than the air fares will be more affordable and you won’t have the hassle and expense of arranging for visas and so on. I strongly suspect though you will have to postpone this ‘budget trip’ to a later date.