I would rather just get a check. I think they use gift cards with strange stipulations like this in hopes that you just don't use it.
I guess I could go to Costco and buy 4 bottles of Vodka. That would leave me $4.40
I could stop at Walmart and buy 5 bottles of the water I mix with it.
That would leave me .45
That's pretty amazing you can calculate the cost of 4 bottles of vodka, plus tax, and subtract in from $60 in your head.
Of course, if we're talking whiskey, I can probably do that too.