I understand the frustration and overly-sweet CL deals like this often end up like this. The "Bid-Over" strategy is a good play to make in cases like this, but it sounds like it would not have worked here (and the other guy would have had to be a moron not to match at $350).
Last year we had a Joust pinball come up locally on CL for $600 ... bidding war (between members of the local collectors boards ... serious nerd drama on the Innernets !) took the price to $1700 ... was on eBay shortly thereafter (and I believe it sold) for $4500 (more serious nerd drama on the Innernets !).
On the other hand, a Computer Space came up (very cheap and unidentified, but we figured it out) and, once the first guy on the boards said that he was in contact, there were no bidding wars or attempts to steal it out from under him.
You never know -- if you want it (and don't mind burning local bridges), make every effort to get it, because, most times, people won't do what this woman did and will go with the bidding war.
Oh ... and the price on the F2K isn't terrible ... it's a fun machine to play, pretty easy to fix and, if you want to restore it, the repros are available/coming ...