If they're not using SNI I agree that it would be expensive... not necessarily that expensive, though. Elastic IP addresses cost $0.005/hour, which is about $3.60/month; multiply that by 40 datacenters and you've got $144/month worth of IPs, not $600.
Problem with SNI is that you lose IE users on XP. In the UK at least, that means entire organisations with thousands of employees such as Lloyds bank and the NHS. According to our stats anyway.
