BA said Dunston was a "key recruit" for Vanderbilt, and he was BA's 59th highest ranked high school prospect coming into the season and Perfect Game's 48th highest ranked high school player. I don't think a "key recruit" for Vanderbilt or someone that highly ranked in the high school class would be totally without some hitting potential, although it probably is raw like you said.....
This sounds like one of those deals where the Cubs will have to overpay to bring him in. I can't imagine him walking away from Vandy for less than a seven figure bonus.
If he wants to go to Vandy, let him go to Vandy. But I don't honestly see why he'd be a 7-figure type prospect.
If he's the 59th HS guy going into the season, the 59th best HS prospect might be the 100th best prospect or whatever overall, given that there are JC and college prospects too. Should the #100 or #120 guy get 7 figures? Maybe if he's sold on Vandy and you want him anyway, you pay 7 figures. But that would seem like a pretty massive Huseby-esque overpay.
Second, being the 59th HS/~100th overall guy going into the season is one thing, being the 59th/~100th coming out is another. From what I read, he had a disappointing spring. So I assume there are another 59HS/~100 overall guys who probably passed him up.
So if he's the 118th/~200th best guy in the draft, is that a 7-figures guy?
My guess is that if he signs, it will be more in the $400-750K range than the 7-figure range. And that it will still be a pretty extensive overpay at that.