Using more or less storage dinamically

bochaco

I'm getting the idea that the gas needed to execute a contract will be somehow influenced by the amount of storage used.
Looking at the "Name Registrar" example contract, the part where the name is deregistered:
;; Otherwise, just deregister any name sender has, if they are registered.
@(caller) {
@(caller)]] 0
[[(caller)]] 0
})

Would that be reducing the effective amount of storage used by the contract and therefore the reducing the amount of gas needed to execute it?

Cheers!

socrates1024

From the yellow paper, it looks to me like the amount of gas needed to execute a MEMORY operation depends on the current amount of memory used, whereas for STORAGE operations, the cost does not depend on the amount of storage used.