Dear NorthernMama and Joe4D,
Fast 2K retails on average at $17-19/bag. A bag has enough material to set a 4" square post in a 8" by 3ft deep hole. You typically need 2 bags of 30kg (66lb) of concrete mix to do the same job, so a bag of Fast 2K does indeed replaces 100-120lb of cement/concrete mix. Thousands and thousands of posts have been set with Fast 2K, so we have confirmed these numbers several times.
Home owners and fence contractors prefer a bag of Fast 2K vs. a couple bags of cement/concrete mix per post because of the convenience and speed. It takes 2 minutes for Fast 2K to expand after pouring in the hole and at that point you can release the post, moving to the next one. In about 30 min Fast 2K is already pretty hard. Fast 2K does not require water and saves a lot of time and physical work to load, unload, carry and mix cement bags as well as clean equipment such as mixers and wheelbarrows.
I hope that helps clarify things.
Last edited by Fast 2K Team; 07-25-2012 at 10:53 AM.