With the four Halloween tonics available from the event (plastic spider, Halloween, concentrated Halloween and candy corn) there seems to be a simple but elegant solution for those of us that the RNG gods just dislike:
Mystic Forge recipe: 250 of each = one endless.
The sheer amount of bags required to even obtain 250 of each puts a massive limitation on this, the account-bound nature of both the tonics themselves and the endless tonic ensures limited impact on the economy, and it at least would make opening your 50 thousandth bag feel like you’re at least still progressing towards something.
It just seems like four slots in a forge recipe and four different tonics is a match that was meant to be, doesn’t it? 
Sinnyil – Beastgate Flaming Charr Mesmer of Doom
That’s goes right in line with my point So for those folks who just are THAT unlucky, and put that much effort into it…yeah?
Sinnyil – Beastgate Flaming Charr Mesmer of Doom
I’m guessing I opened about 10K ToT bags, normal and personal and finally got it from a normal one. I got 250 of each, but by the time you have 1000 tonics, you almost dont need the endless because it’s going to last you until next year anyway even if it’s in 4 slots instead of one.
I dont know about this suggestion. It’s supposed to be rare, obviously, and this would surely make it far less-so. This isn’t a terrible suggestion, but it’s just one of those things that are luck and would kind of ruin the mysticism of it if it were changed.
To be honest I stopped keeping track of how many of each of the items I had, just started dumping them on a bank alt. In your opinion, would it be more acceptable to amend my suggestion to be four stacks of one kind of tonic, and make it four separate recipes? So like, 1000 of the same tonic instead, making the recipe far more difficult?
Sinnyil – Beastgate Flaming Charr Mesmer of Doom