If I understand correctly, disco dust and extra fine non-toxic glitter are the exact same thing. But, the glitter's about 1/4 the price of the disco dust. Is there any reason not to use non-toxic glitter instead?

I can't see any reason at all... but I am certainly no expert. Doesn't the disco dust say that it's for decoration only anyway?

I agree. Disco dust isn't "edible" - it' just non-toxic. Your body won't digest it.... it will still be glittery when it comes out the other end!! lol It's like crayons. Not edible, but non-toxic.

I think disco dust is a little more fine than regular glitter though. Smaller little glittery pieces

That's what I thought, but I am always amaed at the insane prices for disco dust that I wanted to make sure I wasn't overlooking something!

Sparkle poops! I'd sell that as a bonus and charge extra!

Seriously, as others have said, both are inedible. But both are the same thing.

A 5g vial of disco dust costs about $4.25...that's $.85 per gram.
a 16oz jar of regular glitter on Amazon sells for $9.49...that's $.02 per gram.

Just use it only on decorations that the client understands are not meant to be eaten. For family, I've been known to lightly sprinkle a bit over a roughly frosted buttercream cake. Give it a great look and gives me the chance to tell them to look for sparkle poops the next morning. It always makes me giggle to think which of my relatives actually looks.

I've seen a certain baker in my area toss that stuff all over his buttercream wedding cakes. I always laugh at the thought of the guests the next day freaking out!

So is extra fine glitter actually the same size as disco dust?
 

No, it's still a cut or two thicker.