According to that document, they spent ~1.5M eur (1.75 USD) on developer salaries. If we count up all the people in the "Development Team" section (other than the ones paid by grant, which I excluded from the number above), we have 22 full time developer listed. That's ~$80k (USD) / developer for the all in costs, so the actual salary is probably lower than that. US News tells us[1] that the median US developer is getting ~$132k / year. To put that into a bit of perspective, the local gas station by me is paying staff $15 / hour. That's ~30k / year.

As a side note, what the heck is with all the griping about costs in this discussion? So what if it's "just a big CSS library". Don't we want people to be paid good salaries? I swear software developers are one of the only groups of people I've ever met who actively complain about being paid too much money.

[1]: https://careers.usnews.com/best-jobs/software-developer/sala...