How much dried fruit are you planning to take ?
Your not going to need crates of the stuff, certainly not in quantities to justify the time/cost of a trip to sydney and back.
Everything you need food wise for your first hike is available for cheap at coles and woolies in Newcastle. There is often 2 for 1 or 30% off deals every week or so. Wait for those and buy in reasonable quantiy for a couple of trips.
- Dried fruit/trail mixes etc. Even jerky. (have you tried / like jerky ?)
- Carmans muesli bars are awesome. Weight for the coles 30-40% off deals they usually have them atleast every 2 weeks.
- Continental pasta/rissoto works great. (boost with some dehydrated peas etc/salami).
- Coles / woolies home brand is good and cheap.
- I like the vintage cheese and crackers combo. Should be fine on a walk under 4 days, just dont leave the packet in the sun.
- Dont forget a chocolate bar or two. Jelly beans work well also. You will appreciate the immediate energy boost if eaten before tacking a big hill.
EDIT. sorry i just read your post correctly. If it were me and it was my first hike.. Id ditch the all food must be natural etc no preservatives requirement.. A bit of preservative etc is not going to hurt you for 3-4 days. If afterwards you find you enjoy hiking then consider purchasing a food dehydrator. Then you can buy all foods fresh and dehydrate at home in preparation for your trips. Will work out way less hassle and less expensive in the long run.