at what points is Grams Per Dollar (GPD) effective?
 

I'm looking at a rear disc for my Triathlons and TT's.

Weight savings in marginal gains in performacne, but with my weight loss so far, and goal weight being realistic, it might help :D

Remember: This wheel will only see the light of day on FLAT, FAST cources, yes, 1230g is heavy for a wheel. But I have a set of Zipp 404's for the climbing and hilly courses.

Wheel 1 is $450 with a weight of 1230g
Wheel 2 is $700 with a weight of 1060g

so is 170g worth $250 ($1.47 per gram of savings)?

IMO, no, but I'll leave the final decision to El Union Internationale de OCP. :D

I bought the HED disc instead of the Zipp because the weight difference just doesn't make that much difference on a flat TT course. In fact there is some argument the heavier wheel is advantageous due to the flywheel effect. The Zipp may have some quality advantages, but given the limited number of times that I'll use it, it wasn't worth it for me.