I strongly disagree about banning it.
You can view it as a sort of spam if you like, but I prefer to look at it as a way to get people excited and interested about something that they may not be able to directly relate to in any other fashion. Not everyone is drawn to altruistic or humanistic causes, but the ones who aren't still likely have friends and family who will be curious if the word of mouth reaches them. The last thing I want to see is academic elitism permeating this space. It's hard enough as it is just to get people to acknowledge that BOINC itself encourages business use, and I'd rather not drive away ordinary Joes who can get excited about prices even if they can't understand or sympathize with the science angle.
And I say that as someone with a master's degree. Let's be inclusive here, not elitist and dismissive.
It's better to take some steps before it's out of control. One of posts on r/stellar regarding price discussions. There are several more.
As I see, r/NEO recently banned such posts from the main board and moved them into daily sticky discussion and it looks much better now. See rules point 2 right hand side.
It's not about being elitist. r/gridcoin is one of few crypto subreddits where someone critical about some aspects of gridcoin (if he states good reasons) is upvoted. I wish it will stay open and friendly.