I make my coffee at home. Sustainable shade grown fair trade coffee in my parts costs $15.50 a pound. 17g of coffee for a cup is $0.58 per cup. So for sustainable coffee you are off by an order of magnitude.
Not to mention for an 8 oz latte you'll be paying around $0.70-$1.20 for organic, pasture-raised, eco-friendly milk. We're already at a $1.70 for a morning latte.
What is pretentious about buying products that attempt to be better for the earth, and better for your body? It's fine if "coffee is coffee" for you (heck, I've been known to skip coffee altogether in favor of caffeine pills), but there's nothing pretentious about being conscious of one's consumer choices.