If ill buy defenders... dont waste more than 2.5 millions on somenone.
TIP: Buy defenders with high ballcontrol and dribble...because u need security in ur last line. Check the tackle skill too, because players with strog slide tackling can save ur ass in the last second a lot of times.
Good and cheap Defender:
Bixente Lizarazu-Bayern Munich - 1.9 i think.
Mids:
it depends.. if u want a holding mid..,make sure that they have good tackle and passing to built plays. It will be a plus if they have good shooting too.
If u want a winger, check his PACE and LONG BALL for the crosses.
If u want a playmaker, check his BALLCONTROL,PASSING,DRIBBLE,SHOOTING.
IMO the cheapest and very good playmaker in the game could be Thomas Rosicky(Borussia dortmund).
Buy him for 1.5 millions in ur first season if possible and they train him till the end. IN ur lasts season u can compare his stats and ull find what im talking about.
Strikers , well. I dont know , they are a lot of player sthat can be good strikers, they just must have SHTACC AND SHTPWR above 70,,,and they wil surely be of great use. Of course, a shooter of 90+ is better.