The best Royal Oak charcoal briquettes IMO / IME are Royal Oak Chef's Select
I used to be able to purchase these from DoItBest.com for around $22 for a 40 lb. bag, but not any more. Royal Oak lists these food service companies now.
They're also available from Spreetail for $32 for the 40 lb. bag, either through the Spreetail website or through other websites including Walmart.com, Target.com, and
Amazon supplied through Spreetail.
On Memorial Day weekend I found the Members Mark charcoal briquettes which to me are the same briquettes as Royal Oak Chef's Select in Members Mark bags. The price is better than Royal Oak Chef's Select through Spreetail, almost half. The Members Mark charcoal briquettes are sold as two pack 20 lb. bags, individual 20 lb. bags aren't available for purchase but that's OK with me.
Shop Sam’s Club for liquid propane for grilling and grill charcoal.
www.samsclub.com
For lump charcoal I agree the Frontier lump made in Mexico is a best buy value, especially at Sam's Club in the 30 lb. bags. The only non-charoal objects I've ever found in bags of Frontier lump from 2008 forward were small rocks, golf ball size to pebble size, occasionally.
Another charcoal briquette I've used recently that I really like are Master Grill charcoal briquettes made in Paraguay. These are equivalent to the old Rancher charcoal briquettes that were made in Paraguay and Uruguay years ago. I just had 8 bags, 88 lbs., of the Master Grill brand charcoal briquettes delivered yesterday that I ordered Saturday last week on Walmart. com. Since that order was over $35, shipping was free - a Walmart+ membership also qualifies for free shipping.
As always, YMMV.