I'm going to keep copy and pasting this. Eventually someone searching old threads will see all of my responses to, "WTB Windows 10" key threads.
"I don't know why people keep missing this, but if you're buying a Windows 10 key from someone for cheap, they pirated it. Find someone on here that'll give you one for free, an old Windows 7 code (still works), or learn how to use HWIDgen, and never buy a key again."