Assistance with affordable pet care?

Hello everyone. I have two dogs that are rescues. One of them (the brindle one) is showing signs of pain in her mouth. I noticed because I caught her yelping and protecting the area during play. She clearly doesn't want me to inspect the area either. I won't wait long before getting to the vet but I'm concerned about the financial strain that comes with taking care of this. I would really appreciate any information about locations that specialize in affordable minor surgery. Thanks in advance my homies.