Nah, doesn't taste awful.
It's got a heap of nutrients in it (provided it's got decent soil), and a shot glass gives a decent boost (reportedly the nutrient content of 1Kg veges, but I'm not sure of that).
Instead of $3/shot, spend $8 for 10kg of seed, grow it and juice it.
A tray that you see at the juice bar goes for $12 here. Was listening to a small business show on the radio, and they interviewed a guy who quit his job, and cornered a part of the Sydney market, and sells a few hundred trays a day.
Next lady on quit her stressful job, and started snail farming $9/Doz.