I generally aggre with what you say David, but...

So you buy players for 2 purpose:

1) to transfer tokens to game money
2) to spend money on players that improve and can play in your team for many seasons (and keep promoting)
Is true.

YOU NEVER EVER EVER buy a a player with high quality and low markedvalue... It is a complete waste of money. He will not improve (even if he is young), you will get in to bidding wars, he will drop in marked value, whereas the players you keep long term not only takes your team up more levels, but also improve markedvalue season on season...
Is so not true... First of all you have to consider the profit of making it in to the top 4 and having CL next season again. In my league the average player on competing teams have 4 stars, and there is no way I guarenty myself a top 4 spot without signing quality. Also You can trade sensibly in this regard. For example, I just bought a player aged 18 with 29 quality and 1.5M markedvalue for 1.1M. He could be sold at peak hours for 300k profit on a day trade, which is more than I make from most freebees. Secondly, this guy is a class player for the rest of the season, sure he trains like crap, and I'd rather have one with 3.3M markedvalue, but that is just to rich for my book at this time if I wanna clinch top 4 in my league... This guy is still gonna be worth 1.7-1.8M I recon and 31 quality by the end of the season. I expect a 1.6-1.65M sale before the season is over. 500k profit and having a player to help my get CL next season is not a bad way to spend a token in my book.