Tony Hwang wrote:

This type motor is known for failure mode for motor and
controller going out together. Most people who has this
thing in their furnace, they take out 10 year warranty
for that part.

That is all probably true.

If you buy and use it as constant speed blower at an
expense, that is fine for the purpose of experiment
but economy wise I don't think you'll recover initial
cost and if it fails......

In a previous post, I've already roughly calculated that I'd probably
save $40, possibly $60 per year if I changed my PSC motor for an ECM
motor.

The question that I continue to ask is: What is the
"over-the-counter" price of an ECM motor?

I can walk into any hardware or farm supply store and buy a 120v, 1/3
hp PSC motor (for $75 to $150).

Where do go when I want to pick up an ECM motor?

Who sells them "over the counter" ?