We live in a capitalist society where the value and price of any given commodity will be directly determined by the interrelated concepts of supply and demand in that the more readily available a particular resource it is, the less it will cost the purchaser and the converse is also true which is why gold is far more expensive than the likes of coal.
In the context of Winnie the Pooh coloring pages, many parents are a little hesitant to purchase them on the basis that they are a finite resource, in other words, once they have been colored in they will no longer provide any (or at least the same) degree of entertainment and pleasure as they did previously. From a economic/capitalist perspective, such concerns are perfectly understandable, although like anything else in the world, in order to reach a more balanced and accurate conclusion it is necessary to consider all of the different variables that are in play.
Kids love dinosaurs and kids love crayons, pencils and painting. So coloring dinosaur pictures makes a great activity for toddlers, preschoolers and older kids. There are lots of free dino coloring pages available on the web, but the quality varies considerably. If you know where to look, you can get straight to coloring a T-Rex or a Pteranodon without spending lots of time searching.