Book vacation packages with round-trip flights and accommodations for under $400 with these deals from Tavelocity. These offers are updated often. We found a three-night vacation with flights from Seattle to Cancun, with three nights accommodations, for under $375. We also found a two-night stay in Las Vegas, which included flights from Seattle, for under $290. These offers have specific travel dates. Offers change based on availability. Restrictions, blackout dates, and fees may apply.