You can look on Ebay, I have one long arm quilter saved in my favorites for if I ever get a big one done and have the money to have someone else quilt it....
The site I saved charges $50 + $15 shipping to do a twin/full size. $65, with $18 shipping for a queen/king size. Plus, you'd have to pay to ship it all to her of course. They quarantee a two week turnaround.
So it sounds like this is fairly comparable to what you might get done locally, if you know someone.
:-)