During the winter, there are frequently $500-$600 flights (or sometimes even less) to Europe, but once March hits, prices tend to ramp back up for peak travel in the summer.  From time to time, we’ll see good deals to Europe through the spring and early summer, which is the case with this one:

Newark, NJ (EWR) to Milan, Italy: $580 roundtrip through May. 

You can do a flexible date search on http://matrix.itasoftware.com (ITA is a very powerful and convenient search tool for searching multiple airlines, cities, and flexible dates, although you can’t actually book through their site…once you find a fare on ITA, you’ll visit that airline’s website to purchase.)