Hi and welcome to YT!
I think it really depends on your area, but we got Isabella for $750. Females do tend to run higher than males (our breeder was selling females for $750 and males for $550). I do think it's absolutely possible to find yorkies for around the price you're looking, just be patient.
We weren't having much luck and then one day we noticed an ad in the paper and found a VERY reputable breeder who had our Bella.
Good luck to you!