Quoted from CrazyLevi:
You had to know that wasn't gonna work.
It's been like 15 years now. We all know the deal. If anything is underpriced on CL, your chances of getting it are very slim. If you can't pick it up almost immediately, don't hold your breath. If you are hours away, don't even bother. It ain't worth getting worked up about this - you had a "deal" to rip someone off and they got a better offer. You really expect someone not to take it?
After all these years people still refuse to accept that CL isn't some kind of utopian bazaar meant to fulfill our dreams and fantasies. It's nothing more than an online flea market that's just dollars and cents for most people.
It seems OP just needed to vent.
We all know the deal. Lose a deal on CL, miss out on an ebay auction, stub your toe... come to pinside to let everyone here know your sorrows.
For the record, I would honor a deal with someone but I can't fault other people for wanting to get more money if someone offers. A lot of CL sellers are hard up for money so it makes sense.