I got this answer directly from Longoni. Not a very good answer. But after three emails they at least they finally answered.
Quote...
"Dear Randy,
thank you for your message. The main differences are related to the design, to the structure, to the different materials and different type of finishing we use for a cue.
F.e : one star cues have a really simple drawing and the wood involved is only one type. The two and three stars have some more accurate drawings and maybe more elaborated wood.