Cheaper by the truck load

My girlfriend and I buy most of our food from Costco; anything canned, dry, frozen or even fresh if consumed enough is bought there. Our cupboards are well stocked but not in a huge variety but shear quantity. For most things the savings is quite evident - 4x the amount of extra virgin olive oil for the same price, but for some items it's cheaper at Rainbow or Cub. Today we bought 3 gallons of Tropicana orange juice ( I drink OJ like most people drink soda) and 1 gallon of milk so we cold have some breakfast. The OJ is pasturized and does need to be refrigerated until its been opened. The milk touts that it comes from cows who haven't been inject with growth hormones. The milk doesn't even have a dairy label on its package that's the shape of a cubical cylinder to maximize packing effectiveness, minimize bulk. The label is that of "Kirkland Select", Costco's company label, which doesn't bother me but it would be nice to know WHERE the milk came from. Here's some of the problems that i have with Costco: Many of the products are intended to be frozen or have a long shelf life. They're sent from all of the world so that we can have our cheap prices - oranges from South Africa for example. That's a lot of wasted gas oranges that aren't as good as the one's from California. The packaging for damn-near everything extravagant, ridiculous, and superfluous most of the time - a wrapper inside a box inside a wrapper. Almost all of it can be recycled but the cost of initial production seems counter-intuitive to buying in bulk with a simple label. Economically, Costco's internationally distributing seems like it would be good, allowing money to flow throughout the global economy. My milk and OJ probably go through very similar processes before I toss them into a cart. Each is a collection of liquid that was gathered from several sources and then all lumped together before being purified and parceled out for distribution. Again, I have no idea where any of this stuff is coming from, how far it travels from collection to processing, to distribution, to the store... how many miles could have been cut out of the process had I chosen milk from a relatively local dairy, the OJ is of concentrate from the US and Brazil, unfortunately.
I unfortunately don't understand economics or politics well enough to see all the inter-relationships that exist due to wholesale food stores: I know that the little guy has a tough time getting his goods sold and that in politics, more money = more influence, therefore huge companies like Costco must have some part in politics as there direct influence against the farmer, etc. should have a negative impact... surely someone wants them shutdown.