I use wool blend felt (soft) and acrylic felt. The stiff felt I think you are talking about is almost like a sheet of cardboard. I don't use this, as it doesn't mould to the headband/flower well.
I'm in Aust as well and get my felt from Spotlight in the squares, which I think are about 80c - $1.50 depending on wool or acrylic. They have a good range of colours. Or you can buy it by the metre but it is quite expensive $11 - $15.00 a metre.
I use my sizzix machine to cut the circles in different sizes.