Help needed for 'Learning the Game Mission' 'Expectationmanagement'

I have now tried about 3 or 4 times to win that mission and I'm at a loss how am I supposed to win it. At least one of the three AIs already upgrades to a level 3 HQ before the blackmarket even opens up for me. This is something I can cope with however. My real troubles then start in end game - usually I'll buy one of my copetitors and another AI takes out the fourth. Then it starts buying my stocks and the game is usually over before I can buy his (although I never get that warning that a player has X% of money to buy my company - is this disabled when only 2 players are left?).

Also I don't know yet how to find out how other players are trying to make profit - is there some easy way to find out what they are producing?

Thx in advance for any help ...