This suprised me, it's not a bad rate difference.
Still;
1.25% on 800k = 10k
1.75% on 900k = 15.75K
That's a 57% difference purely on interest, your repayments to principal would obviously be 10% higher.
I was quoted in March '09 by serveral different banks, so can't remember exactly, fixed/floating rate roughly about a 1% difference between the 80% and 90% rate.
Having a long standing relationship with the bank you take the mortgage from seems to help with getting better rates.
Mind you, I've had the experience of doing all the paper work only to find just before acceptance, I was convinently told that particular rate was no longer available.
If you receive such attractive quotes, get a letter of offer to make it official before you put all your eggs in one bank.
Again, Banks suck.
And again, good luck with your purchase.
i have 2 mortgages, 1 at 90% and the other at 80%.
the one at 90% is at SIOBOR + 1.75%
the one at 80% is at SIOBOR + 1.25%