Too many things have to line up exactly the way you imagine for this to happen, and I think your scenario is too optimistic as a result. Specifically, the merchants "can now lower their price" but they might not do it, especially considering that the costs of integration with this system are probably non-zero for them.

Wizz is a Hungarian (so: European) airline (since 2003) and girocard is a German (so: European) instant low-fee payment system (it's been rebranded in 2007 from EC-Karte that existed since 1960s). At this moment, as far as I'm aware, you cannot pay for your Wizz ticket with girocard (they only accept Visa/MC/Amex or "co-branded" girocards.)