I think he probably goes in the 8-10 range. There is no question that Ainge has the assets to trade for him if he decides he wants him. Really it depends if Aigne think he can use his assets to get someone established in the league already, and/or sign a viable defense-first center in free agency. I think he'd like to save his best trading bullets to get a go-to scorer at the 3.
That said, if he falls to 8, Detroit should be picking there and have zero need for WCS. I think 16, Young, and the Minny pick would be a fair trade for both teams, since Detroit needs to upgrade its talent on the wings, which should have some good options at 16 (and Young is from Eastern Michigan as a bonus). I'd like to think that is a price Ainge would be willing to pay. (And no, I haven't given up on Young.)