I cannot imagine how you could work effectively without calibrating, for me it is not a waste of money. 

If anything it saves me money because I do not waste expensive paper producing prints that are not as I thought they would be when I clicked the print button. If I were to work with trial and error, printing with no colour management, hoping to get a print that looked like the finished image I saw and liked on my screen, I am sure I would get through reams of expensive photo paper. 

I calibrate my monitor and use the appropriate colour profile for the type of paper I am printing onto. I don't do colour critical commercial work but if I did I would calibrate from start with the initial capture.  

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html