The joys of veterinary care, and the necessary use of emergency vets I'm afraid.
Put it this way: your animal is ill out of hours, and can't wait for care. You're then asked to make the call on a potentially expensive decision that could mean the difference between you animal living, dying or prolonging or shortening their suffering. Whether you shoulder the cost yourself, or have peace of mind that you have a policy in place to cover the cost you know you can make that decision quickly at a difficult time.
Ultimately it's better to not have to foot thousands yourself, so I'd lean towards insurance every time now. If we do get another kitty I'll be pushing for a top tier policy too, as recent experiences have shown its a terrible time to have to even think about cost.