The final G2 Protectobot to be auctioned by the Hartman brothers is now up on eBay: Blades. Since my previous guess at closing value proved incorrect, and because the same guy has won the last three auctions, I expect that the closing value for this auction will be quite high. I expect that the same guy will win this one again, and will push the bid especially high up in order to do so.
Alternatively, it could be the sentiment among many that the four Protectobots should stay together, and so fewer people will bid. That's possible, but I doubt it. Already, the bid amount is at $885, which certainly isn't demonstrably lower than previous G2 Protectobots at this stage in the game. Still, time will tell.