I'm looking for a 4" abrasive cutoff saw and finding that they are
pretty expensive for what they are.

What do these do that make them so much more expensive than a 14"

Must be low volume. A little cutoff saw can do lots of things
that a big one cannot. Like cut small screws, HSS toolbits,
piano wire etc. The blade is only 1/32 wide.

I can also put a slitting saw blade in my coastel saw and cut
thin brass tubing wood, plastic etc.

chuck