Appreciate your willingness to admit perhaps you made a mistake with your initial assessment.
I have no idea what the return would be for G if he decided to leave, but I am confident the team trading for him would "lose" the trade on paper (at least by this boards standards). The team that trades for G I promise will not be dissapointed in his performance though, you can literally play him anywhere in the lineup, combined with his FO % and ability to succeed on both the PP/PK and his 5v5 metrics (which surprisingly have been getting better somehow with age?) and you got yourself a damn good addition to a cup ready team.
The point I am trying to make, if he does get traded, be happy with the player you are getting and dont freak out about "over paying."