Alicia found someone on Craigslist that was selling their ballpit balls for $25 per garbage bag full. I called her up and offered to take them all if she would deliver them. A bit of easy negotiation and $180 later and we were dumping over 2000 more balls into the ballpit. That puts us well over 5,000. When you sit in it now you are up to your ears in balls. We are awesome roommates.