Sounds like a fair price if it's in excellent condition, my sources tell me that you could pay up to $21,000 for a top condition '02 147. Your seller has had the timing belt done rather early, normally not required until 60,000km although they probably told him it needed to be done after 60,000km or 3 years
. That obviously means you will be due in another 60,000km or 3 years (since it was last done) to change it again.
You are doing the right thing getting the NRMA inspection and since it's been serviced regularly with low kays you will probably find the car is in top nick. Better to be safe than sorry!
However, I think your insurance seems a little high. I would have thought you would be looking at $1,400 - $2,000 even for a guy your age. Unless you have a bad record of course.
Shop around a bit though and even try your parents insurance company as some of them will give a discount if mum and dad are insured. You will also find that some insurance companies will allow you to pay by the month which may help, although beware they often also increase the premium for this kind of facility. Shannon's is one exception to this rule. Finally, if shopping for insurance on the web, you may find that some companies will say "sorry we can't continue with this quote online, please give us a call". Don't be put off as it's due to your age and they just want further info. You might even get a cheaper price from one of these companies, ya never know!
Anyway, good luck and well done on choosing an Alfa!