If it's an item I really want that's supposedly already on hold for another person, I will offer $50 to $100 more and immediate pick up. The greed of a seller always over rides their allegiance to someone who claims they'll come buy the item soon.
Afterall, who here hasn't tried to sell an item on CL and have people promise to come and then never show up? You can't blame a seller for reneging on a deal for a more solid deal offering more money.
Cash is king. You want it, get your benjamins together, get in your truck and go NOW! Otherwise, it's MINE!