Foreign players have to adapt - takes time and some don't ever (a lot don't in fact), pace of the game is also hugely different - Allan looks brilliant in Italy, and too slow here, same with Gomes just can't play in this league, look at some of the huge money transfers from France lately - Chelsea, Arsenal etc where they just busted out msssively.
The idea that there's way more value for money abroad often doesn't hold water.
This lad has over 60 top flight games already, and in a near promotion side was their standout player - always a big sign of quality.
Is he worth 25-30m - probably not right now, but he's a better risk than buying two vlasics hoping one will succeed