Here are some suggestions I came up with in a list form, just like nik's thread.
1) Domestic and International Markets
This one is a wild card, so I don't think that this idea will go very far. The domestic market includes players in the country your club is based off of.
The international market is all those other players not from the country your based in.
The domestic market will usually have better players than abroad. You could upgrade the scouts to get better quality players.
2) Make players in market from actually managers, not bots
If this makes a return, I could also suggest a token bonus when the player is going higher than 10+ tokens.
3) Make players open to managers based on their level
I also hope this makes a return as bidding wars are getting bigger for good players.
4) Spend real tokens after 10 second mark
I also don't know about this one, but it could limit bidding wars.
5) Less 3* players
These are some abstract suggestions (except 2 & 3), as I thought about this in about 5 minutes. (so don't bash on me if this doesn't suit the devs)
If you have any more suggestions, I'm all ears.