Yes; that comment was a response to your scenario whereby someone has already decided to purchase the item. You asserted that said person would then surely purchase it in the store, at the moment of the decision to purchase. I claimed that some people are too keen on getting a good deal to do that, opting instead to wait and buy it mail-order or online.

This is unrelated to the probability of my statements being a sales pitch.

Thus, a person might think: "Hmm, is this merely a sales pitch? Perhaps; but even if it is, and it succeeds in convincing me to buy a backup device, I might well still not buy it here and now, because I really want a good deal." They might then conclude: "And so, given that the salesman knows this, and is nonetheless insistent that I should buy it — and is even encouraging me to buy it elsewhere if it'll get me to buy it at all — I should take his words seriously; at least, seriously enough to look into it further."