Thanks for the thoughtful suggestion. I have identified few specific areas that can make use of our product, but as you mentioned engaging with them in a conversation may be the best way to find out.

I just read the article recommended by the other commenter (Joel's article on Segmentation) and it makes sense.

I think I should do the following to start with: talk to potential customers to find out what is critical; identify their price sensitivity; then group the features needed for various customer segments and identify price points.

I guess this will take several iterations to get a grasp, but I think I have a fair idea now as to where to start.