Bafanguy,
Southwest is not a startup. They were around BEFORE deregulation, and they started with 3 (used) 737s. Times were hard initially and they lost one to the bank, but the employees and herb got together and figured out how they would be able to maintain their full schedule with only 2 instead of 3 aircraft, and thus the 20 minute turn that made southwest airlines was born.
All well before the airlines were deregulated btw...
Cheers
Wino