Jack Lowe judges corporate logos and considers their value:
[T]he worth of a logo is a famously hard thing to determine. The very fact that a simple or low-key design often works far better than something intricate or brightly coloured means traditional methods for calculating how much to charge – using things like time and experience – are often thrown out the window. As such, some of the most famous logos of all time have been commissioned for next to nothing, while astronomical sums have been paid for designs most people wouldn't think about twice (not that that's necessarily a bad thing).
The logo for Twitter cost between $2 and $6 – a mind-boggling bargain courtesy of crowdsourcing. Compare that with the $211,000,000 price tag for BP's 2001 rebranding effort, designed to cast it in ecologically wholesome light.
(Image: One of the submissions for Greenpeace's contest to rebrand BP in the wake of the 2010 oil spill. Winning submission here.)