I think a lot of people here are underrating Bastinac's ability, and judging him on his output over the last season.
He has hit rough patch yes. He has been dropped. So was Atley at the halfway point of the year. But he still played 17 games this season. He has played 121 games in 6 seasons, or 20 odd games per year. That's actually a remarkable feat in itself. He also averages a goal every other game, and is a great accumulator of the footy.
Unfortunately, the inclusion of Dal and the 'meat grinder' of Jack, Cunners and Spitta has meant we haven't been able to play him in his ideal position. As a result, his form hasn't been up to the standard that we expected of him. This doesn't mean he isn't a valuable player.
I would only trade him in a deal involving Aish to North. Otherwise, keep him in the side and let him fight for his spot in the side. Given the sub rule is now gone, you need players with his endurance in the side.
I personally feel most people are short sighted and judge players on their output over the last 12 weeks. Over the course of his career, he has been a great player for our club, and if he is to leave, we should be compensated accordingly.