In Australia, no.

Let’s say you’re an undercover cop, and I sell you what I say is 3g of cocaine, but turns out there is only 0.1g in there. I’ll still be charged and convicted on the 3g.

If I sell .1g cocaine I have still committed the regular version of the crime though. Its just that we measure drugs as a final product not the amount of the active ingredient because drug sellers/buyers don’t have a great way to measure that. On the other hand if I sell powdered sugar as cocaine I have committed a different offense.

“a substance (not being a prohibited drug) which, for the purpose of its being supplied, is represented (whether verbally, in writing or by conduct) as being a prohibited drug or a specified prohibited drug, for the purposes of this Act and the regulations, be deemed to be a prohibited drug or the specified drug, as the case requires.”

Nope. Claiming that the 3g of powdered sugar is cocaine? You’re getting done with supply.

Easy. Then we just sell the cocaine while claiming it is powdered sugar. Worst case we get booked for sale of food items without a license.

I believe that fraud charges would be in order.

IDK about Australian law, but in the US, no.