We've raised the issue before of whether ITIL certification offers a return on investment, especially if you pay your own way as compared to scamming the boss into paying for it. For those of you who are self-funded, the total cost may be food for thought. I reckon it is up to $60,000 or even more, depending on your hourly rate, not to mention 4 to 6 weeks out of your life.
[Updated: I was asked about online training so I looked at that too. Courses are much cheaper but if you factor cost of your time it is still a hefty commitment.]