All tandem jumps made in Australia must deploy the main parachute by 5,000ft.
The higher you go, the more freefall time you get:
10,000ft jump = 35 seconds
14,000ft jump = 65 seconds
All skydiving companies in Australia by Law are supposed to quote the total price including "APF Levy" or "APF Membership" and "Fuel Levy".
Cheap prices usually means one of 2 things - ie. tandem factory that gets you in and out as fast as possible and/or costs are getting cut somewhere...