Claimed HP leader is the Kawasaki Ultra 300X @ 1040 lbs wet / 300 hp / 1498cc = 3.47 to 1 and $15,000.00 / 1040 = $14.42 lb. <- that's a really useless stat, but more is better.
Yamaha VXSport (The Rental Unit) @ 736 lbs dry / ? hp = no idea, but 1052cc and $8,400.00 / 736 = $11.41 lb.
3-up Spark @ 421 lbs dry, let's say 450 lbs wet / 90 hp / 900cc = 5 to 1 and $6,300.00 / 421 = $14.96 lb.
2-up Spark @ 405 lbs dry, let's say 435 lbs wet / 90 hp / 900cc = 4.83 to 1 and $5,700.00 / 421 = $14.07 lb.