[quote=@Eklispe]
Depends kinda. It is only when the card is flipped up? Do things that have a cost every standby phase or whenever an attack is made or something get this perk too?
[/quote]

The standby phase thing is a maintenance cost. Those you still have to pay even if Trap Economics is up. As for an attack response...

I'd say it depends on the wording of that card.

Actually, even that may not apply since Trap Economics only works on other Trap card activations, not Trap effect activation, like for a Continuous Trap. At least, that's how I think it works.