If you can't get a friend to be there, and you can't pay an off duty cop to be there, and you're not able to get an ID, and you're not able to talk on the phone, and you don't trust yourself…
Take a 25% deposit by Zelle which links to a bank account
and they can pay the rest in cash
if you are trusting them to come in your home, they are trusting you to not steal their money
Trust works both ways so if they don't trust you to give you a deposit then they are not trustworthy