Pipe Dream: Casting for a "Kid Sensation" Movie

*For the record, this post started out as the response to a question posed in the comments section of this blog. After I realized how long and drawn-out my answer was (some might say "bloated"), I decided that it probably made more sense to make it a blog post.

Someone recently asked who my dream cast would be for a Kid Sensation movie.  My initial reaction was "Wow." That's further down the road than I've dared to even dream. Moreover, it's a tricky question, because in my mind - when speaking of movie adaptations in a situation like this - it all comes down to budget.  Basically, I think Hollywood budgets for the type of film this would mostly get spent in three areas: talent, special effects and marketing. (Naturally there are other costs, but these are the big three.) 

Marketing usually comes to about a third of a film's total budget. Special effects, to me, is often a you-get-what-you-pay-for venture, so it makes sense to shell out cash to a place like Industrial Light & Magic in order to get a high-end product. Bearing those things in mind, you begin to get a sense of what you can do with respect to casting.

In term sof talent, you can decide to spend mega-bucks on a big name like Tom Cruise, knowing that he will be a huge draw for audiences (although that will leave less $$$ to spend on other things). Or you can do what they did in the Harry Potter films: cast unknowns in the lead roles (Daniel Radcliffe, Emma Watson, etc.) and give them a strong supporting cast with lower salary demands (eg, Alan Rickman).  Of course, with Harry Potter, the story itself was the big draw: the books were so popular that the movies were bound to be blockbusters.

Given my druthers (and assuming my books were popular enough to be considered "guaranteed" blockbusters), I'd probably look for the middle ground here: actors popular enough to be considered famous, but not so in-demand as to command an enormous salary. (Someone like Chris Pratt - at the time he was cast for Guardians of the Galaxy (which had an awesome soundtrack) - comes to mind. He reportedly earned $1.5 for that film, and then blew up enough to get $12M for Jurassic World.)

In essence, I don't know that I have a "dream cast" in mind (although I'm sure there are some Disney Channel stars who would probably be suitable for certain roles).  Of course, all of this assumes that I'd have a say in casting; Hollywood could possibly just buy the movie rights - maybe have me do the screenplay as well - then say, 'Shut up - this is our movie..." At this juncture, however, all of this is just wishful thinking...pipe dreams.  Still, you've got to have dreams in order for them to come true.