Plenty ways to build flight time without forking out 100,000!
Most will go down the instructor route, some will do flying sky divers, banner towing, crop spraying, glider towing etc...
Some take many years slogging away getting the commercial licence and ratings and building good quality flight time and experience while others will pay out huge amounts of cash to go to the school with the best reputation for getting pilots hired with an airline with minimum hours. Depends on your own situation, I guess their are many ways to accomplish the goal, no right or wrong way as long as you eventually make it one way or another.
In many ways it depends on luck, being in the right place at the right time, make as many good friends in aviation as possible and sonner or later you wil get a job.
Just my 2pence worth anyway.
ys