You can buy really cheap vodka...or even the small bottles. You're going to need a lot more than you think you will so be prepared to go get either the extract or the liquor. I have not used vanilla, but to me that's more expensive--plus it's brown and would add color to your dust--same issue with Rum or Tequilla if it's not clear.
I buy the cheapest brand lemon extract (make sure it's clear) because I think the lemon evaporates faster. You can also use Everclear which has a higher alcohol content than vodka and I assume would evaporate faster as well. I haven't used that yet, but I haven't been to the liquor store in a while.
I think if I were just going for a metallic look I might try just the pearl luster dust. The green will add a green color to your sage and it may or may not look right. You might think of sprinkling some disco dust over it too to really give it a glittery sparkle...if you want that kind of sparkle that is.
The color 'sage' can vary in range from greener versions to bluer versions. I would start off with Americolor gel color Avocado and depending on the color I was matching either add a tiny touch of black or perhaps navy blue. And I mean TINY touch...like the tip of a toothpick. Sometimes the Avocado alone makes a good sage color.
Others here may have better suggestions...this is what I would do.
Hope it helps!