We live in a very fast-paced society.  We use drive-through windows to pick up lunch and next-day delivery for much of our mail.  Your clients don't have time to waste.  So, if your client is spending time talking to you about a project, it means he or she wants to buy from you.  If your client is constantly telling you, "I can get it cheaper down the street," he or she would be getting it down the street instead of making the investment of time to discuss it with you.