It's exactly how it works. Price is what a buyer will pay, and we've only got one of those. If Pep is fed up with him and you want to get a deal done, that seems like a decent price to me.
I'll have a pint of what he's been drinking, landlord.
Firstly, what evidence do you have that Pep is fed up with him? (And I know you said "if")
Secondly, if you think that 80m euros is a fair price for him, have you looked at the going rate for players of his quality and experience, together with the accolades/medals he has won whilst at City, compared with recent transfers of players nowhere near that standard?
Thirdly, look at the prices being touted for players perceived by the media to be good, but in fact (or my opinion) overhyped - and you can name your own - they are well in excess of City's valuation for Sane.
Finally, it's Bayern who are involved. Their MO is a well established method of trying to unsettle players they want by all the "Dark Arts" only available, it seems, to G14 clubs. I can guarantee that if we tried it, UEFA would be accusing us of "tapping up" the player we were after.
I will be very surprised if (if he does leave) he goes for less than £100m, but nothing surprises me with the club I have now been watching for 60 years.
Perhaps with the management structure we now have in place, we have grown a backbone. I hope so.