I'm with Goldiemom. First off, I always fly in the day before to allow for the unexpected. Second, the airfares are seldom the lwoest. From my closest commercial airport, I can fly Allegiant to FLL for as little as $29 each way (okay, RT after taxes and fees is more like $150). No other airline will touch that and between FLL and MIA, there are lots of cruises to choose from.

OTOH, there probably aren't any LCC's flying from TYS to the remote exotic spots of the world. Just get all your info straight before you book and consider the risk of missing departure.