I have a customer who insists on putting a backup drive in every server bought. They now have 5 or 6 servers in their server room, all with their own drive and software.
It seems to me that at some point (3+?) it becomes cheaper to buy a dedicated backup server and drive and just put remote agents on the boxes to be backed up.

What direction do you take on backups?
At what point should a dedicated backup server and remote agents be considered?