How expensive is it to convert analog to digital (track and controls only)

[MidWestMikeGT]

I actually built my DCC command module using a clone Arduino Uno Rev 3 board, a clone Arduino Motor Shield, and Raspberry Pi 4.  I bought the hardware off Amazon and Adafruit, software was off Aduino, Raspberry, and JMRI (Controller software).  There are a few videos you can use for this.

I saw this thing on YouTube and thought "Why not?"  It works well.  I am able to program my locomotives, etc.  I have not added control to my switches yet.

The whole thing cost me a total of about $100....and I get to use the Raspberry Pi for other things as well 

https://www.youtube.com/watch?v=aa18c0Do1l8

https://www.youtube.com/watch?v=TQogIIad-rk

https://www.youtube.com/watch?v=rtaZ1_L91Bg

Good luck and have fun!