i purchased the 2% sv quints a while back and haven't used them since. 4.5 lifesteal (3 quints) is worth gold 247.5 6% spellvamp is 164 gold even with this change you'd get 7.5 spell vamp which worth 206.25 gold still less than lifesteal quints. you're also sacrificing some damage making it such that you spell vamp off less dmg.
DrCyanide1 votesAnother thing to consider is that while lifesteal comes from many sources, Spellvamp basically comes from two, 
or 
. If you're not willing to build one of these, the only way to add spellvamp to a kit is from those runes. I feel like that factors into the value of the runes a great deal.
Dreadlocks1 votesLife steal quints fell out of popularity when "Feast" in the mastery tree came into play. They're still useful but most ADC's take Attack Speed now for quints. As for spell vamp... I think the only person i know of who has ever used them is SihcEz on Singed. And I'm not sure exactly how serious he was with it. He calls it "spell vamp singed" and builds WoA as well xD.
