How much are guppies?

In pet shops in Australia they range from $4 to $7.50, but with any guppy breeder around the world it depends whether they're a serious breeder and the colouration or effort put into the breeding of that colouration. Mine are selling for $1.50... (I am a serious guppy breeder, just need to get rid of some. They should say; "They breed like guppies" not rabbits) but I have seen them going for over a hundred, and some for $35.