There are probably at least two issues in play. First there are simply far fewer "V"s sold than there have been "B" Standard Rifles and they have been offered in far fewer cartridges.
Except for a very few proto types the "V" first came out in 1970 in the 22-250. The 25-06 followed in 1971. The only other offerings prior to 1978-79 were the 7mm Mag and the 300 Win Mag that were designed to shoot silhouette and aren't really that great of varmint rifle.
The early guns prior to 1976 were designed to be shot with old style long tube scopes and external scope blocks like the Unertl, Redfield 3200 or Lymans. The barrels were drilled and tapped for after market externally adjustable bases. It wasn't till 1976 that Ruger drilled the third set of holes back by the receiver that allowed mounting modern short tube scopes with the now supplied Ruger scope blocks and regular Ruger scope rings.
The 220 Swift wasn't cataloged till 1979 but some did hit the market in 1978.
In 1980 they exspanded the "V" lineup to include quite a few more cartridge choices including the 223 and 6mm Rem. They discontinued the 7mm Mag and 300 Mag about then. There have been short runs of 22PPC, 6mm PPC, 243 and 280 Rem. None of those were chambered for very long and all could be considered scarce at best. The 204 came out in laminate/stainless in 2004 and is now discontinued. The only things currently cataloged as the "V" are the 223, 22-250.. 6.5 Creedmore and 25-06. The current 223 is 1:8 twist to use with the 63 grain and heavier bullets and according to the factory they had no plans to chamber any more 6.5 Creedmores in 2012 (This was in July 2012) nor are they scheduled for any time prior to July 2013. It may be gone.
What it boils down to is simply far fewer rifles in far fewer chamberings added to the fact that guys that buy "V"s tend to be semi/serious varminters and tend to hang onto theirs. After all you get to shoot a varmint rifle a LOT more than a hunting rifle.
Price tends to be determined by age and chambering. In general a guy runs across a bunch of 22-250s and 25-06s and everything else is far less common to out right rare.
Ross