It seems fair to me that the starting base should have a cost, deducted from the starting budget of the player.
This cost could be (at least) the monthly cost of the gates itself.
This rule, if implemented, would forbid players from starting in airports bigger than 200k (with an initial budget of 500k).
For example, if the starting base was a 250K airport, the initial money of the player should be reduced to 500.000-250.000x2 = 0 euro. This way, players will be forced to choose mostly small/medium airports (50K/200K) to start with, otherwise they won't have enough money left to spend in gates acquirement.
Of course, the starting budget could be raised, for example, to 1.000.000 euro, so the players could choose a 350k airport as starting base, but at the cost of having only 300k money left to spend in gates (1.000.000-350.000x2=300.000).
I think that this rule would benefit the dynamics of the game, slowing down the initial economy, thus making the opening of a "big hub" as a target to reach, not a granted initial "gift".
Furthermore, that will reward the initial strategy of the player in choosing the base, whilst currently too many players simply choose a very big airport to have an initial advantage in route prices.
What do you think?