Flash sales to Europe for under $300 roundtrip are still popping up this week. Yesterday's widespread sale to Germany is still available from most cities, and today we're seeing huge price drops from Washington D.C. to both Barcelona and Dublin for just $290-$299 roundtrip on British Airways.
Travel daily from late October through early April, excluding peak holiday travel in late December and early January. A Saturday night stay is required.
These are Basic Economy fares, which include a carry-on bag plus a small personal item. The first checked bag costs $60 each way.
Seats will be assigned at random upon check-in for this price. You may be able to pay a fee to choose a specific seat.
A Main Cabin Economy fare is $160 more roundtrip, which includes one free checked bag, advanced seat assignments, and allows ticket changes/upgrades for a fee.
As an example, I found a flight departing Washington D.C. IAD on Wednesday, December 4, returning from Dublin DUB on Wednesday, December 11, for $290 roundtrip.