There were several in the little fitness section at TJ Maxx, that were PVC-free. They were marketed as exercise balls if I recall, definitely not being sold as birthing balls, but they're the same thing. I bought one and could tell the difference immediately: it didn't stink. But it works the same, looks the same, holds my weight fine, and I'm very pleased with it (plus it was way cheaper than a "birthing ball").
The ball as the word "Tilak" on it. I can't find the box it came in. Sorry. But definitely try TJ Maxx (or Marshalls) and see what they have. I was thrilled to find this one.
Good luck!