The sum is quite small compared to the EU GDP, but that is not what you should be comparing it to. It would make more sense to compare it to the EU budget (as there the additional money would gradually end up to). According to this [website][1] (in the left side infographic in the page) the EU budget in 2011 (a bit outdated) was 129.3 billion euros. Compared to it, 50 billion euros is quite a substantial amount.


  [1]: https://europa.eu/european-union/about-eu/money/revenue-income_en