Edit - cheaper at Officeworks (thanks GG57). Edit: No stock (temporarily out of stock at the payment screen in checkout).

$42 at Bunnings

Basically one year's toilet paper for $35.64 (or $42 at Bunnings). Beats any deals that Amazon can come up with if you are willing to accept the paper being one ply less.

Summarising what's in this article -

one person uses 57 sheets of toilet paper per day.

one jumbo roll (300m) would last 46 days for one person.

eight jumbo rolls (2400m) would last 368 days for one person.

Using maths -

1.4 cents per metre

Assuming 10 sheets/metre then it'll be 14 cents per 100 sheets.