>Is it time for a protected legal definition of "buy" which excludes this nonsense?

I'd go much further than that, "buy" is just one of the completely business washed words which now have no meaning: luxury, unlimited, complete, total, advanced, ... the list goes on.

If you have an army of lawyers and clever marketing team, you can pretty much use intentional ambiguity in English (I suspect any language) to get away with false advertising on a regular basis.