Be sure to share your site with us so we can enjoy the work you put it !
It may be oversight on our part, but I'm not sure what you are referring to regarding Euro signs or words. In the regular classyfrieds plugin there are no references to currencies.
In the paid content expansion pack we do have currencies but you can select any paypal approved currency you like from the admin menu.
Also see our live demo : http://classyfrieds.com/see-listings/
and our expansion pack info : http://classyfrieds.com/classyfrieds-paid-content/
(We do have an upgrade planned where you can edit the language files inside the admin interface. This will likely arrive in V 2.5. If you need to change a language setting in the meantime you can find them in : classyfrieds -> themefiles -> language -> lang_english.php )
If I'm missing your point please elaborate.