If cost is the issue, the most expensive technology is probably iris scanning. However, prices are falling fast, and cameras that can be used for both teleconferencing and iris scanning are already on the market. Of course, as for all technologies, prices vary. Some vendors charge by workstation, others by number of enrollees. Some systems integrators focus on a few technologies they regard as superior, and others work with many technologies.
Some firms emphasize integration with smart cards or Internet applications.
If the issue is user acceptance, the most sensible approach is to run one or more pilot programs, similar to those of the institutions described. It extends to every nook and cranny of an organization. Without policies and procedures in place, purchasing technology is not a good idea. If there's one point on which everyone agrees, it's that security, productivity and quality of care should be considered in systemic terms. Biometric technologies aren't mutually exclusive, whether you're comparing them with each other or with a different technology, such as smart cards.