howtovoip is pretty nice - although it assumes that you can 'voip' ... whereas it's not really a noun. That said, I am sure that consumers would pick up on the meaning of the site. I'd appraise that one at mid-high xx right now.
I'm profess to not being too familiar with what you could download for voip, besides the software ... but that one maybe mid xx
voip downloads has Overture/WordTracker results, and how to voip, although not grammatically correct, sounds nice for a guide site. Mid $xx for each undeveloped, of course would be worth a lot more developed.