Thanks! The trouble is all of these can fail for what I would consider legitimate reasons. Requiring a receipt fails if they just open it, maybe even use it a bit (or not), and wait a few months before selling it, since nowadays people seem to genuinely go through some stuff (e.g. phones) pretty quickly and not necessarily keep or have receipts, especially if they themselves bought it second-hand. Meeting at my home or office is not something I would ever feel comfortable doing, and is generally recommended against when purchasing online. Sharing phone numbers is something I'd only do when the decision to purchase has gone through and we're actively trying to meet up (obvious privacy concerns), etc.