As a "Shelby" part OEM is pricey and hard to find. I lucked into one a few years ago, $350, with damage. Cracked off ends/lower mounting tab which required some repair, so a clean original would likely be at least that...
Check with Perogie or Branda, troll Ebay. I just got an OEM trunk lid and end caps from Branda, $900 for a good used set of the 3 parts needing some minor repair as a general idea of what they go for as a semi-comp.