That's pretty much my position.
I see him as a higher talent and certainly not the worst winger in the league (christ hes not even the worst winger at our club) but there comes a price where you need to sell. We are almost at that point.
Inevitably there will be animosity towards Gordon, but really he is a success story and should spur on future actions.
To prospective academy signings, you can go from Preston reserves to Chelsea on a huge salary in 15 months. To existing academy players- look what can be achieved. For the club, we probably sacrificed a handful of games, then 1/3 of a season where he had low/minimal output, got 1/2 a season of reasonable output and are getting paid 50m in the process. It makes a tonne more sense than continual short term fixes of say James/Sigurdsson etc.