I used a $3 case, 3 $1.75 push button switches, 2 free diodes, free wire from an old broken amp, and a stereo 1/4 inch plug I had from an old project. I don’t know how long it will last because it is certainly not as sturdy as a digitech footswitch, but it also was not $40. Even if I had purchased everything at radioshack to make this from scratch, I’d still be around $10 or $15.
I did have to bend the prong for the sleeve on my stereo jack. And I did have to figure out which direction the diodes go (thank you internet!). And I don’t like how big the enclosure is.
But more importantly it works and really makes the pedal easier to use! Especially with my back brace making it very difficult to bend down to push buttons. I do wish there were a footswitch for saving loops, but that is a minor complaint. I’m sure I’ll have more to share as I play with it!
EDIT: Here are the diagrams I got from elsewhere on the internet. You have to have the diodes for the Digitech footswitch.