How long ago did you sell those players and get good money? The transfer market has crashed in the last season or so and player's are only worth around 1/2 of what they were. Don't worry about it we all bought players a few seasons ago at top $$$. I and i know of about 5 others that lost over 1 mil on 1 player.
Planning for the future? Look at the age of your players...
Calculated risks that might pay off? Look at your last 5 games...
DMI changes differently with different skills? Do you even know what DMI is relative to?