I think I might weigh in here with my experiences.
Sometimes you can try listing a player for what you would like or even what the market price guideline states, problem is, sometimes they just don't sell. This could be for all kinds of reasons, including just bad timing (no ones fault)
I have found that if you bite the bullet (usually through frustration/ desperation to unload) after a couple of attempts, then what I do is list for $1000 or $10000. The reason for this is a little thing that made sense to me after a while (I have been in Business Management/ Sales Management for over 20 years) People love a bargain, and, they also have buying egos!
If you list at a lower price, you open up the market to anyone. Yes the big league teams have more cash, however, the lower league teams have starting bonuses and in some cases other cash stored away for purchases. If you can engage a couple of buyers at a low price and get an ego battle going on then you could be quite surprised as to the outcome.
I don't mind if anyone looks at my Transfers section, they will see that even from the beginning I have been able to gain more than the buying price (even a little more or even in some cases) when re selling. So the theory can work out.
One more thing worth mentioning I guess (again from experience), a guy who helped/mentored me when I surprisingly ended up in Div III one day, you need to loose the attachment to players sometime. He mentioned to me that the guys I think are good/decent players now, I will look back at and see that they pale in comparison to the guys you will have playing for you in the not too distant future. And he was right. If you want to keep moving forward, you have to keep getting better and better. If that is through training and developing guys or buying a competitive team, you are going to have to rotate guys until you find the right combos.
I am not claiming to be Yoda on all of this, just adding some experiences that I have had since I started, I love the aspect of the game that is learning, and one thing I have learned in BB is that sometimes with the best of intentions, because of the human factor and the wide range of nationalities, it came be totally random.
Hitting up the forums and searching for answers is something i did not discover for a while, so you are surly on the right track.
Hope I have been of help.