I doubt the price will be doubled from the original one. Higher probably but no where near the secondary market asking prices for Vision line engines. Some are close to triple on eBay. I’m not interested in the Big Boy but it’s cool to get a second chance every other year if you couldn’t get it the first time for whatever reason.
eBay is nuts with prices for older engines that have almost no electronics in them, depending on what has come out recently. There have been original Mohawks, 18009 #3000 that have been listed up to $1200. Recently there was a VL Niagara(not sure if it is still up out there) for around $2500. They had been floating around $3k or more for some time. VL Big Boys were nesting between $4k-$5k easily. No idea if they sat or if anyone paid the steep price.
As noted however, eBay is nuts, and no one should trust any prices. RickO has commented how some swoop in to buy something cheap only to resell it for a high price. Sometimes they get someone to bite, other times they have to lower it into where they are getting close to what they paid for it.
Original 2014 VL Big Boy was set up at $2700 not including dealer discounts, 2019 Legacy Big Boy $2200. I would say that this new Big Boy would easily hit $3k as a guess, but what do I know. We won't know it until it comes out in the catalog.