You (or anyone else) can subscribe month by month to a single app for ~$30/month. If you cancel before the end of the third month you'd pay $90.
You can get the student all apps program for ~$20/month (first year only) with a yearly commitment; that's $240.
So the month by month program will save you money so long as you are SURE you will stop after 3 months, and REMEMBER to do so.
It may also be worth pointing out that most people wanting to work on video editing in Creative Cloud will use multiple apps, especially Premiere Pro and After Effects. If you are going on a course, they are likely to reference both, and you are likely to need both. That changes the equation somewhat.