We are (hopefully) adopting a very elderly small rescue mongrel - his passport says he is 14 years old but this is the vet's best guess. He has no obvious health issues other than being old and a bit slow. He is a great dog for us in many ways - very calm, doesn't need huge walks, and is realistically much less of a long term commitment than a younger dog. He is also gorgeous 
Given his age, I am expecting his health to deteriorate - obviously I would like to give him a comfortable retirement but if it reached a point where he needed surgery or some other major intervention I would not want to put such an elderly dog through this.
I have been looking at insurance quotes and because he is old most are either very pricey and/or have an excess of around £200 for each condition. I'm not sure whether this is worth going for, given his age, or whether we would be better off just having a certain amount in a savings pot for him?