It helps the 'newbies' develop the culture of reading error messages and debugging....that was precisely the reason the keys were also not added... But if @sigu feels its not necessary anymore we can do away with the $ too.

That's good for the learners. However I recommend then at the end include something like:
"Did you notice that $ will not work at step so and so. The terminal accept only predefined commands...blah blah blah" So that at the end of the steps, the learner will not have to be frustrated as much as I was thinking that the tut was a waste of my time.