Ok so regarding the FHSA accounts I just set one up for my brother.
* You can contribute as much as you want to it, however the Government will only co-contribute on the first 6k you put in each financial year. The max co contribution is $1k (17%), for 4 years, so the most you will get for free is 4k from the government.
* But here's the great thing, it's 4 financial years, not 4 calendar years. So you can contribute $6k each in June 2013, June 2014, June 2015 and July 2015 (2 years + 2 days) and still get the maximum benefit. Be quick though, June's almost over and it takes a week or so in turn around times to get the account and details set up.
* The bank you hold the account with pays their own specific interest rate on the account, you should shop around for a good rate because I have seen variations up to 1%. (We went with ME bank for my bro too).
* Tax on interest earnings is a flat 15%, and is deducted from your account (you don't need to include it in your tax return).
* If you don't use the funds to purchase a first home in 4 years the balance rolls to super, locked away for a very long time.
So merry3, I can tell you from experience that you will not be able to pay a $250k mortgage off in 4 years on $60k a year (assuming you do get a job that pays that much to a grad), without having some sort of significant investment gains or inheritance. You may be able to do it in 7 or 8 but if you really want 4 then your best bet is to be very good to your parents and hope for some help form them.
6.5% is not a competitive rate in this market. I am on 5.14% (bank staff rate) but you should be able to get at least a .7% discount off the SVR which comes to around 5.3%-5.4%. 2yr fixed rates are 4.89/4.99 at most major banks.
Ok so now I'm going to whack you over the head with reality.
You are not going to get a 3 bedder for 400k in 7 years time east of Katoomba. So you are looking at long and costly ($2k per year) commutes. So $60k less tax less HECS less $10k min a year on food and bills (my experience) means you will have $33-$37k a year left over and $15k will go on interest and bank fees and legals in the 1st year, plus you need to buy appliances (don't get cheap shit, buy a fridge/freezer and a washing machine that will last for 20 years). So if you manage to take $15k off the loan outstanding in the first year then you have done well, all assuming you spend nothing else on life in general, again this all assuming at $400k and not $600k which is where prices will probably be knowing what Sydney is like.
But don't be disheartened. You will get pay rises, loans balances go down, things get much easier after the first year. 2.7 years in I have reduced a $270k loan down to $160k (paying over $50k/year at it) and it is on track to be gone by Dec 2016, if not earlier.
Blah I've just typed a long rambling post that might not make any sense, maybe I need a few drinks for some clarity as per my off topic thread.
