Until 1 week ago you could use any telephone number to verify eBay account ( from Spain, Bangladesh, USA, etc). Now, something is changed... If you create an Italian eBay account, they want an Italian telephone number. Nice ****
Try Sonetel. I believe they offer phone number from all over the world.
Or you can look for a burner phone in Italy. Every country has those I believe.
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AGED SUPER HIGH LIMIT ACCOUNTS: 10,000/$1,000,000 and 25,000/$500,000
Sonetel will only provide toll free or land line that is unable to accept SMS. Unfortunately Italian numbers are very hard to get as SIM card can only be sold after being registered to someone. I've been looking for some for weeks and only found 2 (that I no longer have as they served their purpose).
Also you have to provide documents and "codice fiscale" to prove that you reside in Italy to get a land line. It's very hard to find working numbers - almost a nightmare.