It's always difficult for many of us to quote a price on what we offer - service, products. It's a reflection of our own doubt. Am I worth so much? Will people pay for my services? We don't see value in what we ourselves do, so how will people see any value?
Often our problem is that we only see a part of what we offer and not the full. Stretch your idea to its fullest potential and then see what value it holds. Does it offer value in your grandest vision of your service? Of course it does. The problem is that we think small, we think in pieces, not in the full value.
Stretch your idea, your service to its fullest potential, and offer it from that space. That is the real value you will provide. Now quote from that space. You will find it easy to put a price to that.