Actually, it's none of the above lol. He knows someone who works at canon. They are also used lenses, not new but in great condition
So you know someone that knows someone that works at Canon? Your friend could be completely full of crap (most 16 year olds are), just keep that in mind. The 100L Macro is $843 refurbished from Canon, so that would imply that your friend gets 60% off lenses, which is a pretty extreme discount. And most businesses put measures in place to avoid people abusing their employee discount, so I'd be careful with that.
When I worked at Apple you could get 25% off 1 notebook and/or 1 desktop once a year. Then you could also use a friends and family discount of 15%, 3 times per year. But the crazy part was that they could ask you to prove that you owned it if they suspected you were buying stuff to resell.