Burch's latest batch of hand-shaped customs just landed at the Adam Mar surf shop in Montauk, New York. Twelve boards, starting at $1,850 and going up to $2,800. They hit the shop site three days ago. Half of them are already sold. Minus gliders and pickle forks, the batch shows a big range: Psychic Vibrations -esque Squit Fishes, Bigger Squits, Luki logs, Secret Agents, and Reggae Sharks. For those not steeped in Burch terminology, that likely sounds like gibberish. For those who've pored over his site, YouTube clips, and social media, you already know. They'll be gone in days. They always are. Which is exactly why I'm writing about them — and maybe not for the reason you'd guess. The boards themselves are only part of the story. The economy around them, and how he's built his brand, is the bigger picture.…