"I want to think about it."
Pretend to look confused, say to him [but for Gods sake don't answer this question / its unanswerable] say:
- You can't see where I put my discount list can you, I wanted to explain "How Our No Deposit Scheme Works" and to reassure you about the financial side of this deal, and how it works in your favour,--------
But be warned you've lost him, he doesn't want your goods, he has a competitor in mind, and lets be honest you've just walked in on him, and your equipment may not be quality he wants, or he may already have it, so if your so inclined try and sell him something else, or get out, you have I hope another 19 calls to do, and this guy is not going to buy. The reasons are academic.
You've heard them before a dozen times, and with your sales training about YOUR COMPETITORS you should be able to 2nd guess his/ her thinking.