The standard price at Sam's Club is 16.68 for two 23 lb bags. A friend of mine somehow got a huge deal at Home Depot...two 12 lb bags for 7.99 but they had a "buy one (2-pack) get one (2-pack) free" deal this spring. Missed out on that one.
I usually don't get too worked up about trying to save beyond the Sam's price...K is very affordable, burns long, and is readily available (I shop Sam's all the time for other things.) If I were burning 1,000 lbs a summer, it might be different.
JJ