Oi! Hands off...
I believe money in Union Pacific is really just victory points. I can't quite determine from the description what the situation is with Airlines Europe.
In any case, I'm rather looking for a stock game but where there is an element of engine/re-investment. Kids seem to love the cash pile invested to become a bigger cash pile, and I found it satisfying also. I don't think it's too much a problem that cash isn't the victory condition. We're currently enjoying Aquire a lot. But I'm looking for something a little more involved.
Is Airlines Europe the one for me?
Not for the reasons you state. There is no 'investment of money to make more money', and in fact the game is played with quite a subdued economy throughout. In true Alan Moon style, this game is all about the acquisition of the shares.
That's not to say you shouldn't get it, because there are many excellent reasons to.
If you want to watch your fortune boom before spending it on something expensive, try Tinners Trail.