I also learned that the motors they use are specially made by Baldor. The rotors are light in weight
compared to say a rotor in a typical motor with the same horse power rating. That makes them start easier.
A 5Hp model costs $960. The box on top has one or two capacitors. What a ripoff.
It may not be such a ripoff, but it isn't a wonderful deal either. Buying a special motor in small quantity is going to cost a bunch.... And they may even be using special rotor laminations.
My Arco uses a dual winding rotor..... it has a high resistance outer set of rotor bars, and a low resistance inner set. That is sometimes done with motors also. The high resistance outer cage is effective when starting because it is also low inductance. Make it easier to start. At speed, the low resistance bars become effective when the slip frequency is low, and operate like a standard motor.
To lighten the rotor, the laminations need to be special. That requires special (expensive) stamping dies, different handling, possibly different die casting arrangement to put in the rotor bars, etc.
For the two winding rotor, with double holes for the two sets of bars, they need a stamping die, plus special handling and special die casting molds to put in the cast-in-place rotor bars. Then more special handling to put in the outer bars.
Motor companies make standard products well, but specials are just going to be more expensive, even without having to amortize tooling over fewer units.
How many RPCs can anyone sell per year? Especially now with VFDs able to do more things, cheaper. They are going to be a pain in Baldor's (or whoever's) tail, and will be charged accordingly.
