I think it’s hard to determine if this is helping or not. The clients who think your prices are too high (or too low) probably will never contact you. On the other hand, those clients who really like what you have to offer and are willing to pay your rate, will contact you. I never had problems with any potential clients who contacted me though my web site. Actually, I believe that by posting your rates on your web site it eliminates those who are not willing to pay the rate you charging and it makes things easier for you and for them.