I Agree with both - I have purchased a software called Texture Maker which helps a lot in creating customised textures. but even so, natural textures (woods ) are very hard to recreate so buying is a good decision.
The skill is to use a terxture but in a way that others don't.
I too use retuching when necessary but in my work which is in most cases "NEW" images and not aged ones - I cannot use too much dirt in it.
the textures I mentioned are good for new environments and 3D Total's (also have them) are good for the aged ones.