On the other hand, integrators typically give a single quote for a single selection of products. Is this a mistake?
A recent experiment showed that offering two choices instead of one radically increased the probability of a sale. Here's the journal article and below is a video that explains the lessons inside:
Of course, this experiment was based on a single product and not a system.
However, the general principle seems applicable - without any choice, most buyers hesitate and look elsewhere for more options. By giving them a few options, it lets them feel more comfortable that they are getting a good deal.
Practical Surveillance Example
Instead of submitting 1 quote for Axis / Genetec (call it the 'premium' one), offer a budget one (analog kit) and a mid tier (e.g. - Arecont / Exacq).
It's certainly a little more work but now they customer can pick and choose the right one for them, feeling more confident that he is making a full and informed decision.
Btw, price anchoring is a related tactic, by giving one really high cost option, you make the buyer more comfortable about the price / value of the lower cost ones.