In a moment of weakness I almost bought silver yesterday. My hunter wants some ramen noodles. Then I figured out that I could buy the largest package of silver they have, and I still might not get enough bright dust to buy the emote.

I don't have a problem buying an emote outright (and did so in D1). By making everything based on chance, Bungie has lost my money. Thank you, Bungie!

Dismantle all Legendary shaders (minus Raid, Faction, or Trials shaders). You'll get lots of dust. Also, dismantle any legendary Sparrows and ships that you don't use. You'll probably get enough dust that way.

Don't forget about dust you can get from dismantling stuff from bright engrams. I didn't have the salty emote, and I was pretty short on dust, but deleting some shaders and ships I wasn't using got me just enough to buy it.