When does tourist season usally start?

One of our trips to Italy was in April, following Easter week, and while driving up the Adriatic coast we stopped at a cafe at a resort hotel to get something to drink, we thought they wre open. The family informed us they were were getting the place ready to open that week. However, they invited us to sit down, sold us some beers and told us to stay and enjoy the view, no problem. It was great. Beach was great, pratically had it to ourselves. View awesome. A relaxing and memorable afternoon.

Yes, in general it will be busier in Italy in mid-May than in early April. It is more difficult to say whether there will be a noticeable difference in prices, that depends on more variables.

I wouldn't worry about the prices as the Euro keeps going up and up so even if prices are softer in the Spring it will still be expensive because the Euro keeps getting stronger and the dollar weaker. It will be expensive no matter what time of year!!!!!