$1.55 = Apparently a lone shot of espresso. Maybe an iced tea too? It'd have to be a tall or something though, a venti is usually 1.89-2ish. Maybe a cookie type thing or a doubleshot in a can?

I'm frankly a bit surprised that the guitar wasn't nicked the moment Dude turned his back. Doesn't make it right for the OP to steal it, of course...