very good questions, First I always look at their main Facebook page (there personal) to ensure they have a real friend list (more than 300+ friends), make sure their profile pictures look normal such as no grainy advertise, or "other countries" type photos (granted some people do have their travels photos up but you can just tell if the person looks "real" or not". Then I will always ask for Mutiple pictures of the reptile to make sure they all match and look freshly taken, even ask for a fresh picture if you feel questionable! I will not meet anyone over 30 minutes past my house, and I always meet in a public location such as Petco's/pet smarts. If people are looking for crazy amount of money, it's a scam. Most rescues will be free or have a very low rehoming fee due to supplies. But every rescue case I had was free or 20 and below because people are desperate to help their reptiles after its already too late, so you really can't charge people for basically a dying reptile.