Live Sand= full of beneficial critters (ie: copepods, bristle worms, mini starfish, etc) and beneficial bacteria essential for the new aquarium
Dead sand= full of nothing

You could buy mostly dead sand, and seed it with some live. As far as the price goes, a 40lb bag of dead sand is about $30 depending on which brand you get.
Browse the classified ads, I believe that a few members that are breaking their tanks down have some live sand for sale. Hope this helps