Grazie for the prompt response!
Let's see if I understood : when customers place an ad, they can write directly the price, for example, 19,25 and the output in the frontend will be € 19,25 (having previously setted €uro as the default currency in admin panel).. if it's like this, it's ok for me.
Furthermore, the customization for Paypal's checkout or bank wire transfers price output will be supported by your team or it is something I must work out by myself???