And, I'm sure, to a degree it literally is (actual cost) as there are no material costs involved and you can try as many times as you want to make something that looks cool. Sure, you have to pay for the program and your computer, but after that it's all simply your time - which is worth something, but not in the same way that $1000 is.
Sounds like creating digital imagery is about the same as being a writer/game designer, all you need is a cheap but functional computer and enough time on your hands to try and hit the right combination of keys to make up a product that someone else has to correct before publishing.