Komo bought out RouterCIM, and according to their website, it's included with all their routers. Why are they trying to sell it to you if their website says it's included. Man do I dislike machine salesman.
If they aren't going to give you a credit if you don't want it, I'd see if it will work for you. MasterCAM Router comes in different versions, with different capabilities and different prices. It depends on the type of work you'll be doing with the machine. Are you doing casework? If so I'd also take a look at Cadcode.
http://www.cadcode.com