I've been doing this since 2005 and actively making a living from domaining since 2007, I have brokered or sold millions of dollars in domains and thousands and thousands of individual domains. Recently I came across domainindex.com and paid the membership and I must say, I've found domains from that site's tools and have resold them for good profits. One thing I'd love to see is the ability to cross-reference related sales with the domains I'm looking up.
Love... all you need is love.
But seriously... a standardized formula for the valuation of domains would be helpful for selling to end users who want to offer 500 EUR for the short 7 letter .COM that matches what they use as their non trademarked company name.
As always, what someone will pay for it is how much the domain is worth; or how much the second guy is willing to pay for it.
Sometimes it seems people are unwilling or slow to adapt to proven technology or concepts because it seems new or foreign to them or would change the way they approach or see domaining.
But if a new company or product comes along, promising old techniques or old solutions wrapped in a shiny new package (but no longer works or is as effective), some people seem to focus too much on that instead.