That’s not true. Depending on bean extraction and quantity, a standard “cup” of coffee will have 100-200mg of caffeine. Black tea bags have around 40-60. A good rule of thumb is about 4x. Getting shit tier coffee goes for about $8/lb and will make around 30 cups, so about 25c per cup. So compared to the meme, coffee is still more expensive per mg of caffeine.
Edit: on Amazon you can get 200mg tablets for about 8c each. So that would be your best bang for the buck. Semi related, an old coworker would dissolve a caffeine pill in hot water and call it “Mormon coffee”; he was a character.