Pick 18 will be our first pick next year so I think you maybe right.You'll be copping picks or you'll get nothing if you match and compel him to stay again when he goes RFA at the end of 2021. Timing is now a factor for GWS. They wait beyond 2019 and their leverage seriously diminishes. Your club would be better off focusing on other targets that have not raised the notion of leaving (Whitfield & Coniglio)
As for the picks, I think it's fair to want a reasonably high 1st round pick in the deal, so I suspect we will have to bundle up a 1st & 2nd round pick to facilitate that, and provide another 1st round pick as well.