To continue adding to the other comments, I've seen in the large software companies I've worked for that the sales people do a lot of bundling and discounts or

To continue adding to the other comments, I've seen in the large software companies I've worked for that the sales people do a lot of bundling and discounts or adding special services/products/customizations. While they tend to purvey shrink-wrapped apps, there's basically unlimited mixing/matching/customizing that goes on. Further, companies will pay differently for SLAs, license terms, support, etc. Also, it forces you to reach out to the company which allows the sales people to start working their magic (applying pressure, creating a sense of immediacy, trashing the competition, etc).