Bad ESN: Swapping SIM cards will fix it??

[lippstuh]

Alright guys, I'm on the market of purchasing an HTC Thunderbolt second hand. First seller (eBay) shipped it to himself then closed his eBay account.... wow. Then the second seller I found (Craigslist) provided pictures of all the serials except the ESN (not sure if ESNs apply to LTE phones).

Anyways, I'm having a hard time trusting buyers right now. I don't want a contract since I used to work for Verizon and I have an agent line (I pay $28 each month yee). Anyways I read someone say if an LTE phone is blacklisted, you insert a new SIM associated with your own account and it will register a "new esn". True or not?