replacement balls for playskool pop toys?

For instance the busy ball popper, poppity pop musical dino and all the other ones. Does anyone know where else to get them other than through Hasbro's website? I tried looking on amazon, target, walmart and none were available(well not sold through them) Hasbro wants $4.99 plus $6;99 shipping. That just seems ridicolous(sp) for 5 little tiny balls. I would have to spend another 45 to get free shipping   Also a lot of the toys listed are cheaper in stores anyways.

Ping pong balls work just as well in the busy ball popper  
Not sure about the others, as we don't have them. But my daughter had a bad habit of losing the balls from the busy ball popper, someone suggested ping pong balls, so we tried them, and they work perfect! Probably not great for little babies though, as ping pong balls could be a choking hazard.

I might have to try those.. Dd is 15 months old, so I would think ping pong balls would be ok for her.