The cheapest one-way seat from Fort Lauderdale to Kingston cost US$107 when Spirit Airlines was flying. Today, it starts at about US$157 — nearly 50 per cent more — based on current fares on online aggregators.

That gap, visible in cached and recent pricing data captured before and after Spirit's May 2 shutdown, illustrates what aviation economists call the ‘Spirit effect — the removal of the competitive pressure that kept every other carrier's fares in check on the same route.

When Spirit ceased operations, US Transportation Secretary Sean Duffy announced that the Department of Transportation had coordinated an agreement with United, Delta, JetBlue, Southwest, and American to cap ticket prices for displaced Spirit customers — generally requiring a Spirit confirmation number and proof of payment. Frontier Airlines and Allegiant Air also stepped in independently: Frontier offered up to 50 per cent off base fares across its entire network through May 10, open to any traveller, while Allegiant froze fares on overlapping routes. Those windows are now closing.