I think that you are overrating our players.
I have no idea which team would pay 45 for Raki or 25 for Arda.
You guys probably think: when Barca asks for Bellerin or Semedo, they cost 50m, then Raki is surely also worth 50m.
Well, first, Semedo and Bellerin are 22. Rakitic is 29 and declining fast.
Further, supply and demand. Top teams with money, like Barca, are trying to buy Semedo. So, a rich team with money is a buyer, so the price is inflated.
On the other hand, who would buy Rakitic?
Italian teams don't have money, French also (except Psg). Rakitic surely won't go to a midtable Spanish club, plus midtable teams won't pay 45m for a 29 years old cm.
He can only go to Epl.
Also, Rafinha. He can't play in any top team (lack of quality). That means that Rm, Bayern, Juve, Atletico, Psg, top Epl teams won't buy him.
So, again, only suitors for Rafinha could be Roma, midtable Spanish teams and midtable Epl teams. Roma and Spanish teams won't pay more than 10-15. So again, Raki could be sold only to top Epl teams, and Rafinha can go only to Roma/Valencia for 12m or to a team like West Ham for 20-25m.
It is NOT as if every single player today is worth 40-50m. Only players who are chased by Barca, Rm and top Epl teams are worth 50m.
Rafinha is nowhere near that category.
Always ask yourself: in which teams a player xx could play and how much THAT team could pay?