The last time I put together an order to Higginsons I sent out an email to about 10 guys at the club that I shot with regularly. I was ordering 12 pounds myself so I only needed another 10 lbs added to the order. By the time the order was placed and a few other people found out I was doing it the order had climbed to over 60 lbs of powder, 40k primers, and a few thousand bullets.
The last order that was done by another guy at the club ended up growing to over $4000....
Unless the order is contained to a few buddies it gets to be a huge PITA to be the one trying to organize the order.
Usually if it's a group of buddies doing the order they order enough to last them a year or two so you may have to wait a while before they do another one. If you want to get an order going yourself you could put a sign up on the bulletin boards in the main club house and long branch with your email address on it. I'm sure you'll get a few bites as there is always somebody looking for powder. Beware though, if you get a lot of takers it can be a hassle to keep everything organized. Shipping may not be free either, especially if you add any primers to the order. The order I did had a $65 shipping charge added, but between 10-12 guys that's a pretty small amount to pay, just be aware of it so you don't get stuck with the cost yourself.
You could also post something on nlshooters.com forum, you may get a few takers over there as well.
Heck, you may have one taker right here.....I'm stocked up pretty good right now but my buddy is just getting into the sport and may want in on an order. If you get one on the go let me know.
Good Luck!