airfares to Florence this past April/May?

My husband and I, and a longtime friend who travels with us, plan to travel in Tuscany for about two weeks next May. My husband and I were in Florence in May of 2012 and were lucky enough to see the Mille Miglia Road Race run past our apartment - a complete surprise. Now DH wants to see it in Siena this time so he can photograph the cars in the countryside. From what we can surmise, the event will go through Florence and Siena on the 20th of May, so we need to be there earlier that week. We plan to fly into Florence out of Charlotte, spend five days in Siena driving in the area, the next 3-4 days are rather open....either another stay in Siena, go to another Hill Town, or try a trip to Cinque Terra. We will finish up in Florence for five days where we'll be close to the airport for departure. I hadn't started researching flights this past April/May so I don't have that history. Naturally, the flights now showing on Kayak for that period are in the $1150 range (Lufthansa), but I see they're charging in the $650 range this September and for next March as well and wonder if Forum readers have any history as to whether or not the flight charges were down close to that range THIS past May. We're used to traveling off-peak, and May is ANYTHING BUT off-peak in Italy, but September still seems like a great time to travel there (and March can't be all that bad - It's ITALY, so what can be wrong?), so I'm holding out hope that I can wait and snag a really good deal as we get closer.

We went to Amsterdam and Prague this April and found prices about $150 off the normal rate over the Labor Day holiday, so we jumped on them - but certainly not any kind of a difference in rate like this - and they never really went down appreciably - plus we were mixing FF miles and full fares, so we needed to take advantage of ANY cut in process for two tickets.. It would be SWEET to score really low prices to Italy. Does anyone have any history to share? Are these low-cost fares pretty common with Lufthansa? Thanks....