What kind of costs are you talking about? Mineral? Build costs? Planetary Commodities? Just saying a generic “higher cost” doesn’t really explain much.
Why do you believe this is necessary to prevent station spam? (I’m assuming you actually mean Upwell Structures, not actual Stations, because players cannot anchor those anymore)
Does this apply to all structure? What if we already set our Taxes, Repair, and Clone costs to 0 ISK?
You say “up to 30%.” How does it get “up to” that amount?
Why do you believe this is necessary? What about all of the structures that don’t have Services installed, and thus don’t consume Fuel?