I don't believe them either, but whatever — this citrusy blend holds its own against any rum concoction.
Total cost: $29.15
You'll have just enough ingredients for two batches.
Gin - $15.99
Bottle of grapefruit juice - $4.39
Carton of lemonade - $2.49
Bottle of sparkling water - $1.69
Honey for simple syrup - $4.59
Get the full recipe on Distillerista.