I am looking for a resource with somewhat accurate/reliable estimations of travel expenses for popular tourism destinations. I am able to find bits and pieces on wikitravel, tripadvisor, lonelyplanet guides and elsewhere. However, a more exhaustive and organized resource would be much more helpful for all the travelers planning their budget and weighing their options.
budgetyourtrip.com resembles to what I am looking for, but I am not too convinced of the accuracy of their data: according to it, daily expenses in Paris are in average 50% higher than daily expenses in Oslo.
So, it there an obvious and well-known resource that I am unaware of?