The pricing is typically based on the size and complexity of the quilting. Your local quilt shop would be a good place to start when you begin looking for someone. Feel free to call them with your quilt dimensions and they should be able to give you a range. Look at their work and find someone who you click with.
I'm a longarm quilter and I have clients send me quilts from all over the country. Feel free to take a look at the pricing guide on my site. It will give you a good guidline of quilt costs based on size and type of quilting.
Also, you can find a good quilters listed by state on the International Machine Quilters Association website.
Many people love to piece but prefer to let a machine quilter finish it all up for them. Good Luck!