I don't think it would work. Craigslist doesn't offer any guarantees that they'll step in if the seller doesn't ship. There's no feedback mechanism, so prospective buyers won't be able to see if you are trustworthy.

I wouldn't buy anything from someone on Craigslist where I had to provide payment before receiving the items.

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If this is going to be a Christian nation that doesn't help the poor, either we have to pretend that Jesus was just as selfish as we are, or we've got to acknowledge that He commanded us to love the poor and serve the needy without condition, and then admit that we just don't want to do it.

- Stephen Colbert.