I and my wife will flying to DPS from Singapore next week and it will be third flight in less than one year. All flights were on LCC - AirAsia, Jetstar and we always use them - I won't pay more than SGD 125 for 1.5h flight. During sales on different LCCs on sale you can get one way flight for less than SGD 75.

What would matter in your case:

- How much luggage do you have. With LCCs luggage fees end up very quickly
- How much time do you have between your arrival in Singapore and your departure towards Bali. If you buy flight on LCC, or even if you don't, you need to put enough time for possible delays/IRROPs. I would suggest to put at least 20 hours in between.
- One very important thing to notion: Bali/DPS is subject to frequent cancellations and travel delays due to volcanic activity. Last year during whole week around this time the airport was closed. You must have appropriate travel insurance which has coverage for natural disasters. To be sure you should travel to DP at least 36h before your scheduled departure on cruise ship.