Peck in that break through season was certainly a better player in a better side than Charles was during his time at Wednesday albeit playing different roles.
Charles is perhaps more of a natural Premier League type player, bigger and more physical which he needs to be for that CDM role. So perhaps they see his ceiling being higher to justify the £30m.
Peck though, has played a lot more and I think is developing well as a player. He had a tough season last year and was exposed by Selles tactics as he tried to put too much on Pecks shoulders, it affected him. Peck did have a better second half of the season.
Peck for me has a high ceiling and if he can play consistently with a midfield partner then he should also be able to have a decent season.
On the basis of Charles being sold for £30m you’d have to say that Peck is a £20m plus player, which is a little bit mental