IMO, these collection of links type resources would be much more useful if the author curated the list down to something like "Read This_Article for This_Topic" and let people then just google for more information if they need it. Just googling and inserting the top 10 links into a list isn't adding much value.
Who is to say they didn't do a "proper calculation" and result in something close enough to €99 that they just rounded up/down to keep things consistent?
I don't think schofield's response was great, but he certainly didn't pretend the submitter was making something up, he just didn't think the information exposed is sensitive. Realistically this isn't a bug in the software, it's an issue with the design of the invitation feature from a legal/UX standpoint. Either the user sending the information should be aware the information is not private and/or the invitations should expire at some point.