These things used to be called cheat codes, and they were free.
Yup, and now if you use "Cheat Codes," it will be considered a form of hacking where you are breaking a product, one you paid for with your money. They, EA, will cook up some scheme through some law and prosecute you for more $$$$.
"It's not about crudely forcing the player to spend extra with brick wall obstacles, but a more subtle psychological invitation, leaving the option out in the open, like a box of chocolates tantalisingly within reach," Dan Whitehead wrote in Eurogamer's Dead Space 3 review.

http://www.youtube.com/watch?v=Lm_GPkOfVKI
You could have fooled me, you could have fooled me. I can certainly see all weapons being obtainable in a game because Electronic Arts wants to market itself as a "reputable company," but said weapons will have such harsh requirements that people will cave into buying the things.