The price does not enter into Sussman's argument. Maybe it could, given how students tend to be short on money and abhor paying for expensive textbooks, but it doesn't.
> Growing and selling coffee takes time, labour and effort - yet none of that is being reflected or accounted for when we choose to not pay for the coffee we consume.
In my coffee analogy, the promotion of the fair-trade alternative would be based on the fair-trade mechanism for ensuring the lower levels of the production chain receive a fairer share of the income. Whether or not the author pays less or more at the store is irrelevant to the argument.
> Is this a sustainable approach?
For this class? Almost surely!
For some people (e.g. me)? To a large extent (things aren't black and white). Apart from (the admittedly large chunk of) non-free Javascript run by the websites I visit, and some firmware, my computing world runs entirely on FOSS.
For absolutely everyone in every situation? Surely not. That's OK.
Really, the only point that matters a lot here is the first one.
> Does it promote "choosing the right tool for the job", or does it promote blind idealism ("free is better")?
It seems to me to also promote the fact that FOSS is far more compatible with academic culture and behavior. While indeed you may have to pay publishers for access to articles (luckily a practice that's on decline!), you certainly have complete freedoms to build on the work presented in those articles for your own research!
I'd go so far as to say that no closed tool can ever be "right for the job" in an academic research setting! (Although one sometimes does have to compromise when no adequate alternatives exist, especially when it comes to lab equipment – but in the CS world things are a lot better.)
> And why does a university, which takes exorbitant tuition fees, not prioritize the best software for the course (over the one that's merely free)?
I don't understand what MIT's tuition fees have to do with this.
