1

What dates are you looking at?
I had a quick check on utiket and on the 30th Dec' 12, with Lionair it comes to about USD$250 DPS-BTJ via JKT.

2

Another thought is Air Asia. They fly via KL and are very reliable. Looked up a random day in Feb and it was $70 Euro to KL and 50 Euro to Banda. Gotta check specific days though bc KL to Banda doesn't run every day

3

the cheapest way by far-if u book ahead !!is exit indonesia and back in -fly denpansar to KL and KL to Banda aceh with airasia,but if u go in next few weeks probably not worth to go that route but sure will be cheaper than your $ 250 more like $ 120- 150 one way ,check different airlines in bali,usually their promotickets are only available 2-3 weeks before departure (citilink,batavia,mandala,merpati )with airasia u can also fly bali-bandung-medan-aceh but again if u go in the nxt few weeks ,their tickets are expensive,airaisa is cheap if by 3-4 months ahead or when they have the promsals going n,I flew bali-kl-aceh in october for $ 65 one way but booked it 6 months before

4

depends why you want to go all that way for. lots of nice quiet islands, beaches and diving on and near Bali.

5

Flying from Denpasar to Bandung and onward take a AirAsia flight to Medan untill Banda Aceh is a good idea. Another option is to take the bus from Medan to Banda Aceh, in case you have spare time. In order to avoid greedy ticketsellers, just buy online. Nowadays, you can pay for tickets by ATM too. Lion air, sriwijaya air, airasia an garuda fly from java to Banda Aceh.