I don't want to stifle conversation, but I will caution against getting further into the union question.
It becomes intensely political, pretty much immediately.
When not directly political, it becomes intensely personal with some folks blaming unions for the decline of American industrial viability and other folks heatedly justifying/defending union practices.
Lets just say, if you WANT your money going to a union shop, you have your own reasons why.
If you DON'T want your money going to union shops, you also know very well why.
If you don't yet have an opinion on the matter, either research the effects of unionization historically as well as currently -- on your own time, from other sources -- or just don't worry about it and buy what you like for more practical reasons.
Few conversations seem to boil folks' blood faster ... and we don't want that.