Lego figure identification and value

former-member · 2020-11-09T09:51:00.000Z

My son has come across this TMNT mini figure. He told me for day's it was worth something so finally gave in and had a look and apparently it's a comic con 2012 shadow leonardo! Now everywhere I look it says it's rare. How would I go about seeing if it's legit and not a replica or where would I start in even selling it to someone who would appreciate it more than a child. Any help would be highly grateful.