The price of them makes them a tough sell if you need 2 or 3 machines to cover your work, I couldn't put a tilty on the 3t and the 8t and expect it to make sense, but if you can have a main machine that does 90% of your jobs then it's a lot easier to pull the trigger.
2 years in and mine has easily paid for itself in time saved, many a week it clearly saves us a day so the maths is simple enough.
I waited till I could pay for the tilty outright but in hindsight I would of financed the package earlier and it would pay for itself easily.