The best sales people can very quickly identify the biggest pain point for a customer; if you do this it's easier for the prospect to associate money with that pain e.g. "how much it's worth to alleviate that pain".

If something is a nice to have it's not worth that much to them, if something is a must have, it's worth more... try to put your product in the must have, or at least in the "what a pain it would be without your thing" category.