So glad to hear you've seen some improvement already! Once the meds really get into her system, she should do well. Good on the rest. That's key, says my vet-nurse-daughter. Gotta let the meds do their work without putting more strain on her back. Keeping you and Janie in my thoughts.
Steroids are amazing things. I bet you see improvement really soon. And pain meds will just make her that much more comfy. Now that you have the meds, you can look at Fosters & Smith (btw, I've used them for years. Good company, fast service!) and price out what you need. Then if it's cheaper...
Have you had her checked by a vet? Just because the symptoms are there, doesn't mean it isn't something that might be more easily treated than the expensive surgery.
But I know how you feel. Summer before last, my sweet, adorable, luvbug cat, Tuxedo, developed what we thought was a bad sinus...