My favorite drink at work lately is hot green tea, and I make the perfect cup by brewing the tea bags and then adding any blend of citrus juices (primarily lemon, lime, and a dash of orange and sometimes grapefruit), a bit of honey, and a vial or two of ginseng extract.
The caffeine and ginseng keep me going all night long and it is so delicious. I doubt I'm enough of a connosieur to tell the difference between different varieties of green tea, though I did notice it with "white" green tea, which makes a good blend with the regular green tea bag.
Green Tea: 4g Water: 600g Juice: 35g Honey 3g Ginseng: 10g
Cost: $0.50 to $0.75 per 20oz cup