As spring crosses the threshold this weekend in Australia, the domestic ritual of seasonal renewal meets a marketplace eager to meet it halfway. Retailers have aligned deep discounts — some reaching 82 percent — on the tools of home life: the vacuum that clears winter's residue, the mixer that invites new cooking ambitions, the quilt that signals a lighter season ahead. It is the oldest commercial instinct dressed in the language of fresh starts, and for households weighing the cost of renewal, the timing is deliberately persuasive.