Swappa has a 100% refund if you get burned by a bad ESN. I too bought a premium used phone through Swappa without any issue.
>" If you were to buy a device on Swappa that could not be activated due to a blacklisted ESN then you would be entitled to a refund no matter the seller's stated return policy."
I don't think would have helped me. When I got it - the phone worked perfectly. It wasn't until months later when the guy stopped paying the monthly fee and T-Mobile blacklisted the IMEI number.
>" If you were to buy a device on Swappa that could not be activated due to a blacklisted ESN then you would be entitled to a refund no matter the seller's stated return policy."