I need to make the 250 mile round rip into the Twin Cities and do a bulk buy... maybe in Dec when I have some money coming in...grab 6 sacks of GP, 2 victory, 2 2 row... Simpsons GP blows away the others I have tried. Ordered 10 pounds from Ritebrew to see if quality was any better... still looked like bottom of the grain silo sweepings... dusty, dirty and full of debris. Pass! I cleaned it best I could and lost 1/2 pound to trash.
250 miles sounds very doable. Our group buy is only an 80 mile RT for me, I go once or twice a year.
Make sure to pre-order/call your supplier well, well ahead (2-3 weeks), so
they can order it from their distributor, while allowing enough time for getting it delivered. Then double check they actually got your full order in hand before venturing out.
Unless your supplier's shop is very large, I doubt they keep enough stock for those kinds of orders at any time.
Don't forget to negotiate a bulk discount before ordering anything.

I'm serious, 10 sacks is a fairly big order.
I hear you on the Simpsons GP, I would not want anyone else's GP either.
Sad to hear your TF from Ritebrew was so dust and dirt laden again. 1/2 a pound of debris in a 10# order is totally ridiculous and inexcusable! There's no good reason for that. You should talk to them about that.
I just checked the bottom of a half used sack of TF Optic, it's clean as can be. I found one 1 inch twig in it, and a little bit of clean grain dust.