In Australia, that's very hard to achieve because the residential energy market is heavily regulated specifically to _avoid_ exposing low-end consumers to spot pricing.
In at least WA, NSW, QLD and ACT you can go on time-of-use residential tariffs.
And driers (and washing machines - which use a considerable amount of energy particularly if they heat the water internally) typically already have timer-start functions.
And driers (and washing machines - which use a considerable amount of energy particularly if they heat the water internally) typically already have timer-start functions.