I'm afraid Afobe's record in the top flight simply doesn't stack up. He started well for Bournemouth - three goals in as many games just after he joined - but finished 2015/16 on a run of 1 in 11 appearances. Followed that up with no goals in his opening 10 league games of the following season (as well as a couple of blanks in the League Cup), went over a month at one stage without getting a single minute of action in the league (wasn't injured either, just not picked) and ended up with six goals which frankly, is pretty paltry.
He was a major signing for them and now, 18 months or so later, he's probably fourth choice when everyone is fit, no-one would say that he has proven he can do it in the PL, in my book that is a flop. Do £10m strikers often go on a sequence of one goal in 23 appearances and get away with it? You wouldn't write him off for good at that level but really Bournemouth have no right to be demanding an increase on what they paid. Well they can ask, but no-one is going to pay it.