Hypen, JOM missed almost 3 years with knee issues and has been managing it ever since. He is very clearly not as fast or explosive as he used to be. He has had to rebuild his game to accommodate his body and play as more of an inside midfielder and recently, as a half forward. he is at far greater risk of injury and not likely to be playing good footy well into his 30's as a 4 year contract would require.
As for Sharp, GC want the future 2nd round pick we received off North which is effectively pick 20. That is so far above what Sharp is worth, it's laughable. I rate Sharp and did in his draft year. however he was a pick 27 who isn't able to get a starting gig at GC after 3 seasons. I wouldn't give anything more than around pick 45 or less. Wait for next year when he's out of contract and GC are happy with something reasonable rather than trying to fleece us.