I'll add, that crossover can be instant if you are single, and can put up with flatmates for a few years.
You could even have your mortgage fully paid in this low rate enviro, with only your deposit tied up as your payment.
Right now, a $400k mortgage would be $15k interest (rent). $300pw + say ave $50 rates/ins.
By the time rates rise, who knows, 7% again means economy should be healthy and your earning power in 5 years will be higher too. and your mortgage has already reduced.