Just to add; if you go the postal route, always go with the countries postal service, basic rate with tracking.G'day and welcome to the forum.
Have your aunt post the baccy to you. Declare it as 'hobby supplies' [which it is]
I'd recommend posting in packages no bigger than six tins or 1lb bags.
Since the scamdemic, it's not ever been easier to get baccy through Customs here in Oz [I got over a dozen orders through over the last year before one was intercepted]
AFAIK, unlike Nanny State Australia, it's not illegal to post tobacco to the U.S.
Priority/express and private co's like DHL and FedEx get the most scrutiny at Customs for some reason.