Here are some suggestions and their predicted ratings, some are mine, others are from previous posts from arsenalrocs. majority of the players should get their rise by no later than November.
Jack Elliott (Philadelphia Union): 70 -> 77, is worth 100k in SM.
Nick Lima (San Jose Earthquakes): 70 -> 77, 100k.
Julian Gressel (Atlanta United): 70 -> 75/6, 80k.
Tyler Adams (New York RB): 70 -> 76, 240k.
Kyle Fisher (Montreal Impact): 70 -> 76, 80k.
Ian Harkes (DC United): 70 -> 76, 160k.
Rasmus Thellufsen (Aalborg): 70 -> 76, 240k.
Viktor Tranberg (Nordsjaelland): 70 -> 76/7, 240k.
Vladimir Screciu (CS Universitatea Craiova): 70 -> 76, 240k.
Anton Walkes (Tottenham on loan at Atlanta United): 70 -> 73-6, 240k. (depends on when MLS get reviewed, the later the higher)
If you don't mind 72-73 players, following players may be worth it: (75+ rise)
Maximilian Wober (SK Rapid Wein)
Dario Maresic (SK Sturm Graz)
Kristoffer Zachariassen (Sarpsborg 08)
El-Hadji Kane (Sandefjord)
Per Steiring (Sogndal)
Latif Blessing (Sporting KC)
Raheem Edwards (Toronto FC)
Ballou Tabla (Montreal Impact)
Jordan Jones (Kilmarnock)
Greg Taylor (Kilmarnock)
Danilo Acosta (Real Salt Lake)