Around 120 million for three players is a great deal, especially if you look at Roma's situation and the quality of the players.
Salah is the best of the three, but will never be world class. Too one dimensional (but he is great in that dimension). They've with Berardi a good replacement.
Manolas is overrated, yes he is good, but he is also a 'hot head'. He can kick someone in his ass out of nothing 40 million = good cash.
Paredes isn't even developed and is most of the time benchplayer, 30-35m is the best deal of the three. Really weird and dumb choice from the players to join fucking Zenit of all places ...
Roma has some serious FFP problems and debts. I think Monchi has the job to make the debt gap smaller and buying (cheap) young talent to build a potential Dortmund-like team.