What is the best deal you ever managed to snag & how did you actually find it?

[Jenny80]

Everyone who pays close attention to deals and discounts tends to have at least one genuinely impressive story of finding something at a fraction of its normal price, whether through pure luck, a well timed clearance sale, a mispriced item that somehow slipped through, or simply the patience to wait months for exactly the right discount window before finally pulling the trigger on a purchase.

The method behind finding a genuinely great deal varies enormously too, some people rely on dedicated deal tracking apps and price history tools, others simply keep a mental list of items they want and check back regularly, and some deals are found through nothing more sophisticated than pure accident while browsing for something else entirely. What is the best deal you ever personally managed to snag, and what was the actual story behind finding it?