Isn't this sui generis, followed by carded Lizard, Iron Man, Green Arrow, Aquaman , and Aussi Wonder Woman?
It's an astounding price to me, and I wouldn't spend it if I had it. But grails drive some collectors. If the buyer has painstakingly assembled and curated a high-grade MOC set of Mego WGSH and this was an (final?) item in a set, I can understand it. It's his money to spend, no different than a luxury watch, jewelry, or vehicle. Those things don't interest me, but this item did to the buyer. He may never recoup his "investment."
If I have only $100 to spend, and an item I want sells for $300, of course I'm disappointed. But even if covetous, I'd try not to judge the buyer personally. I've been in situations where I was upbraided for opening carded figures. My collecting impetus has always been to assemble the nicest loose sets of Megos I could--and if I chose to open figures and mix and match parts to do it, I did so to my satisfaction. It was my money to use as I saw fit, and the same goes for this buyer, too IMO.
WANTED: Dick Grayson SI trousers; gray AJ Mustang horse; vintage RC Batman (Bruce Wayne) head; minty Wolfman tights; mint Black Knight sword; minty Launcelot boots; Lion Rock (pale) Dracula & Mummy heads; Lion Rock Franky squared boots; Wayne Foundation blue furniture; Flash Gordon/Ming (10") unbroken holsters; CHiPs gloved arms; POTA T2 tan body; CTVT/vintage Friar Tuck robes, BBP TZ Burgess Meredith glasses.