The following is a basic Lotus Sametime 8.5.x server deployment.

How on earth do you sell this monstrosity to customers?

Well, the Sametime Gateway is optional, so It is not part of the basic install. Also, most of my customers are not going with a 1 to 1 machine for every component. To give you an idea:

1 Machine for DB2 and ST System Console
1 Machine fo ST Proxy Server and ST Meeting Server
1 Machine for Media Manager
1 Machine for ST Community Server
1 Machine for LDAP

So I just went from 8 to 5. Domino and ST Community Server doesn't use too many resources so you can put it in with the Media Manager or DB2, so one machine less (4 now). Also, Based on the size of the organization and number of users you may consolidate a little bit more. I tried all components in a single machine with multiple IPs and it worked - not the fastest - but it works.