The late fall and winter are cheaper months to fly to Paris.
March 30 to May 25 th are shoulder times for many airlines May 26 thru summer are high season months.
I did get those prices coming up two months ago for the Mid May departures. I bought in early December. I was told the flights were filling up fast. The consolidators were not getting any better deals because of the fact that more people are buying tickets and mostly dfrom the airlines web sights.
From Seattle I got $890. for mid May and for end of June the consolidator was able to get me a ticket for $1200.
I was told it did not make a difference on all airlines if one left in a lower season and returned in high season. They will charge one for the high season rate.
I was also told that the flights might go on sale in January and February but maybe only a savings of $50.00 at the most if they even do go on sale!
I was looking for March in December and found flights from Seattle for about $560.
All prices have seemed to really gotten higher maybe because the fuel is higher( or just that is what the market will buy and they can get!)!!