I'm flying SFO-CDG 7/17-7/30 F class via a United Saver award

. But the rest of my family is flying SFO-CDG 7/21-7/30 (flights 926 & 927) in Economy with V-Class fares. My question is this- is there a way to upgrade a V-Class economy fare to E+? Either via miles or cash. Looking at their seating assignments, it's only the return flight, where they have seats 33EFG, where it really matters.
Thanks-
--Mike--
Chain Reaction Bicycles
www.ChainReaction.com