Sure, it only took me about 60 hours of tinkering, fabricating, and running around all over the place.
So I reckon I could do it for about 3 grand LOL. ($50 an hour)
It's a case of I wanted one, there was no such thing, so I bit the bullet.
To answer another question, although it's explained in the vid, tempered glass fragments and solvent form the abrasive medium.