You should look into roasting your own beans! You can roast just the amount you need, ensuring you have the freshest beans, and green beans are cheaper to buy than pre-roasted beans. Green, when sealed, keep for a long time, so you can buy in larger quantities for cheaper as well. Then roast half a pound if that's all you use in a week, so the beans are truly fresh when you go to grind them. The flavors, man! mmm
If you feel like getting quite involved, you can even do it in certain hot-air popcorn poppers.
it'll cost the same.
I predict you'll make more drinks than if you bought it at your local coffee shop
It'll still cost less. Why? Because he'd simply be having more for the same price, and it will probably still cost less.