Just forget about the Exora, Santa Fe and Rondo.
They're utter crap in the long run.
Exora even with turbo is gutless on the highway especially with 4 adults onboard.
Santa Fe and Rondo may be cheap to buy and seem to have alot of "accessories" but overtime the upkeep won't be worth it especially with Estima and Serena available within budget range.

Estima the most headache part is getting the right spec because basically recon dealers bring in only two spec the 2.4 and 3.5, although the 3.5 v6 would be nice to have on the highways the maintenance bill and roadtax isn't too friendly, but usually it will be the one with the highest spec like power doors x2, power boot, rev cam, etc.

I think the 2.4 would be better for you but beware as some dealers advertise a 3.5 as a 2.4 just to grab the customer to the lot then try and use his salesman skills to close the deal. pitfalls for the 2.4 is the spec, some spec really kosong only 1 power door, some got 2 power door, those got power boot can be considered full spec but hard to find usually it is a 3.5 advertised as 2.4 to lure customers.

As a used car the 3.5 and 2.4 are priced around the same so it really depends on what you want.

The 2.4 has a similar engine to camry and is the more common one on the road so cheaper upkeep. Might be a little sluggish in town with start stop traffic with a full load but on highway it is capable enough.

serena is also a good buy, the hybrid part is like F1 KERS system where it is just used as a boost for pickup, just drive normally and ignore it you can even turn it off......the battery for it is very small coz it is just meant as a boost not a true hybrid....if the hybrid system fails totally it just reverts back to a regular 2.0 no biggie. uses the same 2.0 as the teana/sylphy which is why the electric boost is needed for some oomph. all in all should be pretty cheap to upkeep and cheaper roadtax than estima but imho it is rather ugly.
When people say spacious mpv they're not looking for "c-segment" mpv's like stream/wish/isis/livina/exora.....they're looking for "d-segment" or full size mpv's like estima/grandis/serena/odyssey   
i think you can do better.
my sister got a mitsubishi asx for around AUD7000-8000 i think it was only about a 3-4 year old car.
since you're new to straya lemme share something with you.
locals never buy a car they cannot buy by cash or pay for it within a year or less.
i would say that i30 is on the higher end, unless you really like it then different case.
if u looking for a good deal, that ain't it.

Hi Bro, appreciate your comments. However, estima and serena is out of my budget. Within my budget i believe i might able to get very very old estima which is likely 2006 years, as for the serena, i found one used serena last week, went and see, condition so so, but the price is almost 95K OTR. Did you think old estima worth to get as well?

Parts wise should be fine
But I don't think it's worth the hassle
So don't ever get rear ended
95k doable for estima

http://www.mudah.my/vi/49360847.htm
Serena still quite new won't drop so fast

you do realize that both vehicles are completely diferent.... maintanance and running costs are sosososoooo diferent...