Being frugal for the sake of being frugal is not very useful. Your time has value and you could spend it on learning / relaxing vs investing it into saving a little bit of money here and there. Meaning, sometimes spending more means you get more value, sometimes it doesn’t.
Having said that, we all come from different walks of life and maybe for someone this advice will be genuinely helpful. I know I have resolved to using this myself on a couple of occasions myself for various reasons.
Here it is - for 2 cents you can get an hour of usage of a m3.medium spot instance! You also need to pay for the EBS storage but according to the docs it comes with a 4 GB ssd, which will set you back 40 cents per month of usage! That is 40 / (24 * 7 * 4.5) cents per hour.
Why would you want to take advantage of this? For one thing, it is quite neat to use a fully functional instance at such an attractive price. But, more importantly, chances are there will be many, many uses where this instance will be perfect for this course.
Do you know git? If you are planning on using course materials and do any development yourself, this is a tool that you probably should learn. You can do it easily on this instance.
What about python? Do you understand how data gets moved around for the training and the commands in the notebook? Another perfect use case.
Do you know pytorch? I am seeing pytorch for the first time in my life! To familiarize myself with the API, do a couple of tutorials, I don’t need a GPU - not sure if the smallest m3 instance available is the best choice here but who knows. If not, I can spend the extra 0.5 cent per hour and get the m3.xlarge. At 2 vCPUs and 7.5 GB of RAM it is a force to be reckoned with!
And yes, you could probably do a lot of this on your local machine, but doing this on the instance gets you in the practice of using a server in the cloud and you get to learn all the bit associated with this! How to create the instance, how ssh works, what can you do to edit code, how to install stuff, you might even be interested in learning tmux, etc. All the really good things especially if for some strange reasons you are stuck with a local Windows machine 
(still you probably should be installing a VM or a linux subsystem ASAP but that is a biased opinion of a random person on the Internet so take it with a grain of salt 
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Sorry if my post seems a little bit light hearted but it is Tuesday morning, I am super happy that this course is happening and grateful that I am part of it, so guess it is okay if I let some of the good mood seep into the post! A happy Tuesday to you all and maybe some of the above information you will find useful!