Do you know that Jackson has already played for an average club well not that average before Chelsea? What I'm saying is that he has come past that level. He's suppose to be one of the best in the EPL when he arrives but he couldn't get things right even when the manager Enzo Maresca always see him as the best nothing impressive came out of him and you don't expect him to continue wasting chances and the manager continue to give him more time till the club stop competing for the EPL title, no it can't happen.
He has pace but he's always off color whenever he comes face to face with the goalkeeper like a one on one situation, Jackson doesn't have it at all so that amount should be reduced to maybe £25m because hebis the ine who reduce his value.
Like you said, Saudi clubs go for experience and players with good form, now Jackson doesn't have all of it and any team that spend that amount on him should go back and take their balance because he'll definitely continue making things hard for whichever club he finds him self.
I honestly want to be surprised when I see him banging goals and doing the impossible. Currently Manchester United have him on their radar but that doesn't mean they'll be happy to cash in on Jackson with that amount, his performance doesn't fit that amount.
You shouldn't be stressing yourself over this, Chelsea as a club rate him very high, that's why they place so much figure on his head. It's true that it's too high for an average player like him but that's didn't disputed the fact that he is better than most of the strikers at Manchester united, it's left for Manchester united to either negotiate his transfer fee down or look for someone else, it's not a do or die affair.
I know that everyone that dislike him will just think that he brings nothing to the table due to his wastefulness in front of goal, but honestly speaking, he is good, but his finishing is what has let him down all through his stay at Chelsea.