I see you're in Melbourne, I don't know where... I bought new windows a couple of years ago, the cheapest place I found was on Boundary Road in Braeside, near Mordialloc. I can't remember the name of it but it's just near the big roundabout at the corner of Governor Road. Our windows were also an irregular size and they just made them to order, no problems. I can't remember the exact cost, but I do recall that they were markedly cheaper than any other quote I got. And the windows were great quality!