To the adopter of Hope, the kitty, and anyone else seeking low cost spay/neuter. You can search for your area at www.spayusa.org. However, not all low cost clinics are listed. I'd suggest you advise clinics you use to register so this site can be more accurate.
As has been recommended by many, PAWS clinic is very good, Dix Animal Hospital is also very good and both are relatively inexpensive. Check the others listed in the screenshot below to see what their rates are. I'm unable to locate my screenshot of Dix Animal Hospitals contact information so if anyone can post that in the comments, please do. Hope this is a benefit to all seeking low cost spay/neuter.