Keep in mind: smaller airports tend to attract low-cost carriers, which have lower fares by nature, but they also typically have more limited destinations and fewer daily flights, which can account for some of the fare differences compared to larger airports.
Do airfare prices drop closer to departure?
Timing plays an important part. Specifically, plane tickets usually don't get cheaper closer to the departure date. Instead, flights tend to be the most inexpensive when you book between four months and three weeks before your departure date.