Like anything in life, you can find it very cheap to very expensive. But it's all relative really and everyone will have a different opinion as to what is 'reasonable'.
In Italy, using information based on my experiences, asking colleagues too, the prices generally range from €300 to €3000.
Is the €3000 wedding photographer worth 10x more than the €300 one? To the person booking the expensive one, yes. Absolutely. To the person booking the cheaper one. No. Absolutely not.
At the risk of ruffling feathers, this is what I've found is frequently the case for photographer's (full day coverage, digital only, assumed):
€0-€500 - New wedding photographer starting out. They're trying to build experience and their portfolio. This is really the danger zone. You may find someone great! You may find someone terrible. Research is key in this zone.
€500 - €900 - Slightly more experienced wedding photographer. Got a few weddings under their belt. Typically "weekend warriors" supplementing their main income. Usually using reasonable equipment and will deliver a reasonable set of images for the money.
€900-€1800 - Wedding Photographers in this category should have plenty of experience now. Should be able to show you a variety of weddings from all times of the year, in all weather conditions. Photos should be on a quite high standard. Usually full time but on occasions can be a very experienced weekend warrior. Most people should be happy with images in this price bracket unless you are extremely discerning.
€1800+ - These should be highly experienced wedding photographers. They are delivering an extremely high standard of photography and/or have a very developed and unique style. They should have more weddings under their belt than they can shake a stick at. You're booking based on a variety of factors including style, brand, images, discretion, and personality.
Please, try to keep in mind that you'd better try to send inquiries approximately 1 year in advance, to have the chance to book the most requested church, the most requested Villa or the best wedding photographer, during high season for weddings, in Italy (from May to October).