Your biggest gain when using UD pulleys is the crank. This is because the crank pulley is relatively heavy, especially the dual mode, and to UD it requires a smaller pulley whereas on the alt. and the PS you need a larger pulley. You're looking at 4.5 (single mode) to 7 (dual mode) lbs. vs. less than 2 lbs. for an aluminum pulley.
Personally, I run a UD crank and PS pulley. There are gains in both mileage and power and (IMO) the steering feel is much improved.
If you guys want to add a crank pulley, I'll do that too.
Yes, I will sell a PS pulley seperate as long as I get the minimum quantity.