While your response is valid leader-of-the-band in my ebay experience you can barely get an ebayer to read a title or description for any listing let alone be searching the boards for a thread that might pertain to their situation. 

And in reality, I would say that in these situations MOST people are not scammers. So my advice is to MOST people. In reality even if you had a receipt signed by the collector and a photograph of them taking the item, not only would the person picking up think you were a complete nutter, I doubt if it were queried 6 months later whether you had this information carefully filed away to produce on demand.

Doing a bank chargeback is not as simple as people may think, it's frustrating, time consuming, and the banks just don't give you your money back without a tedious and lengthly investigation.

I've been on ebay 8 years, had heaps of items paid with paypal and picked up and have never had the slightest worry. Even for very expensive items. I understand these things happen, I just think the general distrust for such an innocent exchange in circumstances such as this is unwarranted.