We usually fly during the NH Feb. or April vacation weeks which are a week after your dates and I usually get the tickets for around $250-$300 by getting them right around when SW releases the dates. This year they (all airlines) look higher and I am thinking they will be closer to $380.
When using SW, their prices only went higher, and I never saw a drop in price for our trip dates, so if the price is under $350 on the morning they are released I'd grab them. I compare SW release date with JetBlue to decide which airline to use.
SW can, but in the last few years not so much, have good prices when they are released, and they fly n/s out of Manchester, but not Boston.
I need to get tickets for Dec. 1-8, and the prices have been sky high for JetBlue. SW opens booking tomorrow and my fingers are crossed.