That in bold is a terrible idea. I'd be unbelievably p1ssed off if it took me 3 transfer windows (over an entire YEAR) to sign any player.
I do like the idea about having difficulty levels though.
Here are some of my ideas from another thread:
think the prices of some players can be utterly ridiculous just because they are "important first team players", this needs to be addressed.
I'd like to see more details in the tactical aspect of the game. For instance, I'd to be able to tell my deep-lying playmaker specifically to spread the ball to the flanks, or to feed it to the striker.
I'd also like to be able to give players instructions, as well as being able to give positions instructions. Say I have Milner and Young in my Villa team on either flank. I'd set Young's instructions to beat the full back at every opportunity and get the cross in, whereas Milner would have a more defensive setting. I'd like to be able to tell them to switch flanks regularly throughout the game without Young taking on Milner's instructions and vice-versa (i.e. Young becoming more defensive minded and Milner trying to beat the full back).
Say I had a midfield of Scholes and Fletcher, I'd like for them to take it in turns getting forward rather without them having to "Switch positions" with each other, as it were. Fletcher would see Scholes has gone to support the attack, so he'd stay back, and vice-versa. Because I'd give Fletcher tactics to close down far more often than I would Scholes. Maybe have a "stay back when needed" sort of thing implemented for open play.
I'd also like to be able to challenge players. To be able to say to Wayne Rooney "If you score 30 league goals this season, you'll get a 10% contract increase".