I agree it's worth it, I currently have my 2 insured, one of them had a cyst which needed surgical removal (approx £300).
Jeremy who passed away earlier this year had almost £600 of treatment after being referred to a specialist for treatment... theres no way I'd have been able to afford it myself!
If pet insurance didn't exist, I don't think i'd have my 2 bunnies, 8 cats and 2 dogs!!