There have been a couple of instances where Apple slightly reduced the price of their products for Black Friday shopping. Other than that, their products are never on sale. Not that I've ever seen.
If you want to save money on what is, for all intents and purposes, a new product, go to Apple's refurbished page.
Look to the left column for the device you're interested in. The choices change rather often according to what Apple has for sale at the moment. Apple does whatever is needed to make a refurbished item look like new. I got my iPhone 6s there for $459. At the time, that was over $100 dollars cheaper than a new one, which are now $449 for the same 32GB version.