Not everyone is on Pinside all the time and the default setting for email notifications seems to be off as I never received any from Pinside.

I tried to buy a Wonka from a fellow Californian here, it was the perfect deal for me because I could have traded my game for it, drop one pick one all in a day

But it didn't happen because the seller didnt check Pinside for a week and by the time he did I already committed my pinball to someone else.
I also suspect some people don't close their ads to avoid paying the fee.