Take a look at AMS some day. Typical day sees dozens of Fokker 50s, ATRs and Do-328s used to fly shorter or less dense routes where jets are not economical (or to fields that cannot take a jet).
jets: faster, more power per engine
So, for a large aircraft or long distances jets are the way to go as you can get there faster using less engines.
For short hops and small aircraft, props are the cheapest solution.
I wish I were flying