What quotes from Lord of the Flies show the respect the boys have for the conch at the beginning of the book?

The boys revere the conch and it grants power to whoever holds it.

Early on in their island explorations, Piggy and Ralph find a conch shell.  Piggy tells Ralph that it is valuable and "ever so expensive," and shows him how to blow on it to make noise come out.  It is as a result of this noise that all of the other children who survived come toward Ralph. 

“We can use this to call...

The boys revere the conch and it grants power to whoever holds it.

Early on in their island explorations, Piggy and Ralph find a conch shell.  Piggy tells Ralph that it is valuable and "ever so expensive," and shows him how to blow on it to make noise come out.  It is as a result of this noise that all of the other children who survived come toward Ralph. 

“We can use this to call the others. Have a meeting. They’ll come when they hear us—” (Ch. 1)

Since the conch had the power to bring them together, it develops an almost mystical importance.  The conch begins to symbolize leadership.  It is because Ralph had the conch and used it to draw the boys together that he seems special, and perhaps wise.  The boys elect him leader because he appears to fit the role perfectly.  He is good looking, and he is the one holding the conch.  This is why Ralph is chosen when the one who seems to have the actual leadership skills is Jack.

But there was a stillness about Ralph as he sat that marked him out: there was his size, and attractive appearance; and most obscurely, yet most powerfully, there was the conch. (Ch. 1)

Ralph is described as “set apart” by virtue of having blown the conch.  The boys see it as a special item, so much more than a "toy."  It is for this reason that the conch is chosen to be used during meetings to control who speaks when.  Again, the conch d power.  It grants the one who has it the power to speak, and thus leadership of a sort.

The conch is symbolic not just because it is valuable monetarily.  It is loud, and strong.  It gives the boys a sense of purpose and togetherness when at first they were scattered.  The conch itself is not that special.  It is just a shell.  Yet the boys are grasping at the straws of civilization, and to them it is everything.  When the conch stops begin powerful, their little society has descended into chaos.