My travel motto is "Helping the country economy one coffee at a time".  

Last weekender I did, I picked a place a bit further away than I normally go.   Bought 2 coffees while I was travelling and 2 while I was at the campsite.  Its not much but every time I do it thats another $6 into a local economy somewhere.  

And yes, I could easily stop by the side of the road and brew my own but its not going the break me financially if I spend a small amount of money on the way and if it helps to keep some small country business operating then its worth it.

Just for the record, most of those coffees are absolutely awesome and better than I get in the big smoke.