If the link I saw really is your own portfolio (
Professional Banner Designs Portfolio By DecentBanners) and the price list is accurate, then anyone who thinks you're too expensive is just not a serious business person. Put a little more effort into your
SEO (title tags and on page copy)
You're biggest mistake is promoting at webmaster forums. Go lurk around forums where NOBODY has your skills. If I was a gourmet chef I certainly would promote my services on a gourmet chef forum. Go hang out where you are unique.