I use it on all my firearms, it really seems to make a difference it cleaned up my fathers old Winchester Model 88 like it was brand new, and it smells good too.
I've purchased it both at the store and online. It basically evens out once you calculate shipping into the mix. You definitely save some bucks buying the larger size bottles/jars, but you don't need all that much. It goes pretty far. Compared to Hoppe's and other traditional cleaners the improvement in the smell and performance is well worth the extra money. Try it once, and you'll switch for sure.