Fly from Los Angeles to Las Vegas for $39 round-trip, including all taxes, with Spirit Airlines. This is a new route for Spirit, scheduled to begin May 5, with fares on sale now for $1 each way. That makes for a base fare of $2 round-trip, with taxes and fees making up the rest. One fee you might find particularly odd? A "passenger usage fee" of $16. Huh? Usage of what exactly? Apparently, this is the fee Spirit charges for tickets purchased via their site as opposed to those bought in person at the airport ticket counter. That may be a slightly annoying way to offset a crazy low fare, but even so, this is still a good deal along this route. See our fare details for more info.