Italian Covers Question

Looking through the postcard collection I have were some foreign letters. Here are three that I'm looking for a ballpark value on. ebay search of sold examples was confusing on these particular stamps, being high to low. The letters are included in these covers. Any thoughts?

All appear to carry the same stamp. Two have the same railway cancellation for Florence. This all suggests these are common stamps (probably basic inland letter rate) and also common cancellations.

People on ebay include the people who think leaves falling from the trees in their gardens are rare and ask hundreds of euros for them. prices realised are the better indicator for value.

However, if you see two offered at 10 cents and one for 10 euro, you can bet the 10 euro either is one such optimists, or has a cancellation that is rarely found.

Thanks NSK........

The 15c slate stamp with this design comes in 3 variations, all pretty common used and on cover. Based on the dates, these would all be Scott 123, the lowest valued if on cover. For this kind of material, Delcampe will give you a better sense of market value.