Well that depends what coffee means to you, if you are the type of person who dont care about coffee that much, for you the coffee you drink at home, Dunkin Donuts, Mc Donalds meehhh "its all the same shit" yes of course coffee is not that important to you, Im sure $6 is too expensive for a coffee for you.
Every time Ive been out of the country and I see a local coffee shop I get exited, Im truly curious and interested in drinking and tasting different blends of coffee and I enjoy the local flavor, smell and taste of each coffee. To me drinking a good coffee is better, much better than drinking any type of alcoholic drink at any bar. So to answer you question TS if they present to me a unique type or blend of coffee from a place Ive never visited before, and Im at a very comfortable and nice coffee bar, sure I dont see it as an out of this world idea to pay $15 for a good coffee, shiiit Ive paid more than that for stupid drinks at a bar many times in my life!