Ah, you can still send/trade brewing supplies to other people, even after you've used it as long as you haven't used it on a potion. There are some brewing supplies, like the gummy and the sticky goo that you can't use on other people's potions, but others like the calming powder, you can. It's just easier to send the supplies you want to trade though.

Also completing the daily festival tasks will reward you with a lot of chocolate coins, a regular vial holder, 6x brewing agents and if you manage to finish them all, a mystery catalyst- which is 20k right now.

By broker prices, the calming powder would be 8k, the gummy tail is kinda cheap right now, but lets put it at 1k, and the sticky goo is around 2.5k. So a total of 11.5k. I can trade you one of the catalysts you're looking for if you add a bit of either gold or chocolate coins to that. For gold it'd just be 8.5k. For chocolate coins, it'd be 21.

Edit: Just saw your edit :P

The sugar and spice and 2 gummy tails come to around 3k altogether, calming powder and sticky goo are the same, so plus another 10.5k for a total of 13.5k, which brings the supplementary gold or chocolate coin cost down to 6.5k for gold or 13 for chocolate coins.

250 cc is good.

So, it's 2 vampiric morkkos, the qitari, and 2 dusky dawn nixis?

Yep!

Sent, happy fall fest!

I have 230 chocolate coins. Also I sent one of my gummy puppy tails to someone else.

That's fine, I only need 120 for 3 catalysts. Unfortunately, I just traded the only Qitari to someone else, but I do still have both the Dusky Dawn Zolnixi and the Black Widow Sylvorpa you can buy for 80 coins. Unless you want to buy a different catalyst in place of the Qitari one?

I want the luff enchanted lake
I have :
Calming Powder 5x
Reactive Crystal 2x
Vampire Dust 2x

I'll trade it for the 3 calming powders :)