Hey Giovanni
I’m not too familiar with multiple currencies WooCommerce however I have done extensive testing with WPML.
If you are using a single currency per language then it would be quite straight forward to set up I think.
In WPML head to – Translation Management -> Multilingual Content Setup -> Custom Posts
enable translations for “Search & Filter”.
Then in the Search & Filter admin screen, you will find your existing search forms in your default language. Edit a Search Form.
On the right in the Language meta box, you should duplicate the form for each language you need it in. Then, edit these translations and make sure you select “translate independently”.
Now you can go in and change all the text in the search form, including the currency symbol for each language.
The only drawback is that the translations are no longer synced with the primary language, so if you wish add or remove fields from the UI for example, you must do so to each form manually.
Thanks