Remember, you are a mercenary fighter pilot. After you complete missions, they give you money. In the results screen, they show you how much you got paid, your total, and anything you unlocked.F4 ia bad indeed but i choose this one for a only reason hes fastes of all 3 planes j have free. When do i buy new plane and which ones? I will try to change that thing with camera following. I dont even know where i have money, how i purchase plane, parts etc. I just put some part on plane i dont even know which one is it lol.
Let me check the aircraft tree, but I think as soon as you can buy the F-16, switch to that. That's gotta be better than F-4.
I think somewhere in the hangar before sortie time, you can buy planes and parts. Also in hangar, you can read the parts descriptions and look at the attributes bars to see what performance boost the parts give.
If you spend wisely, by the time you finish the game once, you will be able to afford the F-22 or other end of the branch high tier plane. I think the first time you play, they give you an extra money reward.