I actually went on to sign Cerny and Halilovic before reading the responses on here. Not sure how, but when I inquired about Halilovic they came back and didn't want a transfer fee. I know he's technically a free agent in the game but I did have to stump up for Sanches. I also signed Nelson Semedo at RB from Benfica. He was relatively cheap if I remember.
My final signing was Yussuf Poulsen, the young Danish striker from RB Leipzig. Again he's without a club in the game but did cost around £17m. Not sure if you guys have any experience with him but he's a complete beast. He's 6"3 with 87 heading, 87 speed and 89 explosive power. His attacking prowess, ball control, finishing, physical contact, jumping and stamina are all good too. His pace and ability in the air allow you to switch tactics mid match without resorting to subs. The only downside is he doesn't have his real face, something I've been spoiled with so far in PES 2017.