Yeah, but that's the secondary, and to be expected. But MLS - especially for the coming season - has already jacked up primary prices for Messi games, and removed them from season ticket packages (or rather they have inserted language that if a game against Miami is scheduled it won't necessarily be included). And the trend in concerts (Taylor above all) is to mark things way up so that the artists and promoters get more of the cut (even as they, like teams, also go into business with the secondary sites).
I don't think Ohtani moves the needle in quite the same way as Messi (and certainly didn't with Anaheim including when he was supposed to play here in August), if you're only going to see him you only get four or five ABs and that's it right now, whereas Messi is in the action for most of the game and could easily account for half or all of the memorable offensive plays and goals. But we already have dynamic pricing based on which team is playing and I'm sure Ohtani's Dodgers will rise to the top for most teams. They are certainly already locked in for season ticket holders (including three of the five Phillies partial plans).
His first home game in a Dodgers uniform, on Opening Day, would obviously be insane no matter.