Planning on going with Extralite hubs for my sub Kg wheel build. 

Front Hub: Extralite Ultrarear 49g 20H
Rear Hub: Extralite Ultrafront 135g 24H
Spokes: Sapim CX-ray 4.5g
Nipples:  Pillar .38g
Rims: Reynolds KOM 225g

Projected weight:  49+135+4.5*44+.38*44+225*2 = 848.72g

That’s a savings of 1050 – 848.72 = 201.28g for approximately $1250 or $6 per gram.  Terrible

It isn’t all about the weight though.  The stock Reynolds hubs leave a lot to be desired and these Extralite hubs will fill that void quite nicely.  But even then that’s a lot of dough for very little gain (or loss).