I would be careful saying that the popularity of Halo dwarfs MOTU as a blanket statement. You could be specific by saying "with this generation" - but as a whole, I would challenge you on that statement. There's a reason everything is turning up 80s right now. It's because the kids of the 80s are not front and center as adults, and the market knows that we run the show and we are the one that have the cash flow at the moment. I would argue that MOTU dwarfs HALO by a landslide if we look at the overall stats and not just where MOTU sits within pop culture. Even at that, with the new documentaries on Netflix, and shows like The Toys That Made Us, there's an increased awareness of who MOTU is, and the nostalgic wave that the current gen is being exposed to with movies like Ready Player One, you'd be surprised at how many youth are in the know of who He-man is and how quickly they are becoming attached. Top that off with the fact that the 80s kids are now watching MOTU on Saturdays with their kids and handing down the mantle - I feel like MOTU has a really big chance at being revived, not even rebooted.
All that aside, $240 for 3600pcs works out to .06 cents a brick. That's literally half of what LEGO charges for the Millennium Falcon. I feel like a company that "not LEGO" charging half of what the main brand charges seems more than on point, especially for what they are offering. I was pleasantly surprised at the quality of the Wind Raider - which my 6yr old son picked out and assembled himself, btw. Let's not forget that the MOTU empire was built from the ground up, with only a toy line that had zero backstory, all by marketing to an audience of 5yr olds who had to beg their parents for these toys. Now, you have 5yr olds coming around to MOTU that are equally as excited to buy, but instead of begging their parents to buy, they are backed by parents who let nostalgic reasoning dictate the money in their wallet. Sounds to me like Mattel knows exactly what they're doing.