How would you judge if someone refuse to use escrow his reason ro refuse is that 20$ is a small amount of money.
I am cautious because people here will try to scam 0.01$ if they get the oportuinity
He is probably trying to scam you because of refusing to used an escrow. And eventhough its just $20 that you are saying a lot of scammers will likely take it. And believed me, there are hundreds here who have been scammed much lower than $20 because they trusted the other party. So you have every right to be cautious and try to used escrow so that you will prevent yourself from being scam. And if refuses, then don't do the trade, simple as that.