My Mod and Spaceport

I've recently read an RPG manual concerning space campaign, and there was a nice description about different type of space port.

I've thinked about it a little more, and todav I've written this idea:

There are five type of spaceport, or, better, five Class, starting from A (the littlest), the B, C, D and then X (the biggest).

Spaceport Class A cost 1/10 normal space port, take only 100kt space, has a 0% bonus on resource generation, has a sight range of 2 and a sight level of 1.

Class B cost 1/4 normal spaceport, take only 250kt space, has 5% resource gen. bonus, sight range of 4 and sight level of 2.

ecc... ecc...

Why I've added resource gen bonus, sight range and level? I've thinked about the meaning of space port. A space port is a facilities where ship land... in mass. Resource bonus because bigger spaceport gets less waste of time, bigger space where store resource when they arrive in the main world of the system. So less waste of resource. Sight Range and Level because a facility like this will have some sensor, don't?

What do you thik about this? I've not playtested yet, but I will soon. And then I must modify AI to make intelligent use of this...