Initial reaction: that's a huge deal. Like, one of the biggest in draft history huge. Not only is the money big, but it's also a big deal that he is already on the major league roster. The M's pretty much forfeited all the team-controlled years, which are the ones where a player is typically a bargain. The combo makes it a clear victory for Scott Boras.
I will write more in the morning, but in the end pretty much everyone signed, and it took figures well above slot recommendations. I'll have more cogent thoughts in the morning, and hopefully more concrete details.
Ackley is a Mariner though. That's good news. The price was really steep, but it's hard to feel bad that he's under contract. It will be easier to put the deal in perspective once more details come out on all the deals.