If I purposely lower my teir, say from 2 to 1, for what ever reason, when I'm ready to go back to teir 2, do I need to pay for all the requirements again? Or just the cost to go to next teir?

Am I understand this correctly? My opponent attacks and I defend,, I get 3 sl and he only gets 2sl, I determine hit location and damage, and he loses an advantage?