Wanting to buy a Kindle Paperwhite, which is currently offered around $170 - according to PriceHipster this the cheapest recent price, though it is not advertised as a sale.
Previous bargains and forum posts do not reveal any discounting pattern (compared to, say, UE Boom which is discounted every few weeks).
Do I buy now and cross one Xmas present off the list, or wait and hope that the pre-Christmas / Black Friday sales mark it down further.
It doesn't go on sale at any regular pattern. Best way to get a discounted price is to wait for one of those eBay sales and get it for $140-150 from Officeworks.