Southwest Airlines discounts a selection of 1-way fares starting at $49 as part of its Click 'n Save Sale. That's among the best sales we've seen from Southwest, although we saw a few select flights as low as $29 last week. Flights must be booked by August 19 at 3 am ET for travel through December 14. A 10-day advanced purchase is required. Note that most fares are valid on Tuesdays and Wednesdays only. Blackout dates and additional taxes and fees apply.