The flaw with this thought process is that you overlook the importance of a player's attributes and place more import on his level of talent. More like Berbatov was more talented that Chicharito but even a flawed Chicharito was more useful to our side because he had more pace which suited the team.
Kamara is a natural holding midfielder, he can come in and balance out our midfield and that could could good enough to raise the level of the team as teams won't be easily walking through us. Say we spend £10m on him in January but he hopefully settles and that allows us to drop £80m on Bellingham, would you still demand a higher rated player?