I've witnessed people pitch me a product and then downplay their own abilities in the same meeting. Why would I buy services from someone who doesn't believe in him or herself?
All you need to know when selling a client a product or service is what makes you different from your competition. If you would focus on this aspect, instead of pricing, you would have more sales. All you have to do is explain who you are and what you're selling. Add how it can solve a customer's problems. That's it. Keep the pitch simple, short and compelling.