The following analysis documents the increase in Jetstar at-airport baggage fees as compared to pre-paid baggage fees, for Jetstar's Sydney to Honolulu route. Note that for very heavy bags (40 kg) the increase in fees is over 1000% (i.e. more than 10 times the price) for the very same bag paid for at the airport as compared to one paid for at the time of purchasing your ticket. Note that the table formatting didn't copy well from Excel ... hopefully you can follow the logic / analysis. All are in Australian$.
Baggage Weight (kg) Pre-paid Fee (P) At-Airport Fee (A) Fee Increase Ratio = A/P*100%
15 $35 $100 286% [Escalation ratio = 286% for a 15 kg bag.]
20 $39 $225 577% [Escalation ratio = 577% for a 20 kg bag.]
25 $44 $350 795% [Escalation ratio = 795% for a 25 kg bag.]
30 $50 $475 950% [Escalation ratio = 950% for a 30 kg bag.]
35 $65 $600 923% [Escalation ratio = 923% for a 35 kg bag.]
40 $70 $725 1036% [Escalation ratio = 1036% for a 40 kg bag.]
For the Sydney - Honolulu route, at-airport fees = A$100 for first 15kg plus A$25 for each additional kg. If you really want / need to fly Jestar, make sure you buy more than enough baggage allowance at the time of booking your flight. OR, just don't fly Jetstar as advised by this website's name. Buyer beware!