Engine Preheater - any good?

Matt Barrow wrote:

This "economy of scale" argument doesn't always explain the
perceived excess in price. Some things in aviation really are
ripoffs.

Agreed, so how does that translate to the item in question?

The item in question appears to be an electric space heater you could
buy at Kmart, Target, etc. for $20, with a couple of hoses attached to
fit in the cowling of an airplane. The price is $299. If I'm right and
the profit margin is around 1000% per unit, this strikes me as
excessive. And THREE HOURS to preheat?!?! The Kmart preheating solution
I mentioned in an earlier article can do it in two or less.

The only rip-off is the prices for parts/equipment mandated by the
FAA standards (i.e., seat belts that cost ten times more than for
automobiles, even though they are the exact same thing.

So NOTHING in aviation outside of FAA mandates is a ripoff? You might
want to rethink, or rephrase, those words.

Jim Rosinski