Very much agreed.Gutherson is better than Edwards defensively, effort in general and ball playing and playmaking (massively). Edwards maybe slightly better with his support play but that's it. Honestly it's night and day. Gutherson is worth at least 700k. Edwards lucky to be worth 500k (I don't think he'll even get that at Penrith).
Gutherson has been in the top echelon of fullbacks for multiple years but he can play other positions.
I agree he is easily worth 700k. Not sure about 900k. It all depends on how you structure and spread your cap. But i can certainly see clubs paying 900k.