'10 female spider and mojave will run you about $150 - 200 apiece. Shop around as prices seem to be somewhat variable.
As far as breeders go - check out NERD or BHB Enterprises (the Snakebytes TV guys). Both have good reputations and are high-profile breeders in the ball community. Otherwise, you might check Fauna Classifieds Board of Inquiry for breeder reviews.