how much is the estimated amount when making 1.25V - 37V 1.5A Variable / Adjustable Power Supply
Using LM317 ??

 

Depends upon where you are and how elaborate you want for the case and meters. The electronics are cheap. It's the transformer, case, meters, heatsink, and other hardware that are the main cost.

Note that you can't go up to 37V @ 1.5A with an LM317. Look at the data sheet of output current versus voltage across it. Also its power dissipation will get very high at a low voltage output with 1.5A, requiring a very large heatsink.

 

1. Write down a list of every component (electrical or mechanical) you intend to use. This is traditionally called the “Bill of Materials” or simply the BOM.

2. Find a source for each and every part.

3. Copy down the prices from #2 into #1

4. Sum all the prices in #1. Don’t forget to account for multiple parts when and where used.

That’s it. No magic to it, just some dog work.

 

Expensive bits (in order of decreasing price): Transformer, filter capacitor, heatsink, box to put it in, rectifier, pot...

By the time you get to the chip, it is almost free by comparison.

You might get something out of this thread....