I'm on the fence. We have PetPlan which is super expensive but covers chronic conditions for the rest of their life. DCat is now 15. In his younger years he had to have the following:
2 inches of tail amputated (caught it on barbed wire we think) £1500
Stomach wash, scans, overnight for three days after poisoning - it was touch and go £2,500
Stomach pump after eating lillies £1400.
I'd say the cost of treatment outweighed the premiums until he was about 8/9.
Aged 10/11 he developed arthritis. The excess is £135 and I have to pay 20% of all costs. His meds are about £70 every two months, and he needs a blood test for a couple of hundred every 12/18 months. The insurance contributions bring the costs in line with a cheaper premium which brings peace of mind.
At 15 his quality of life would take precedence over expensive treatments and I don't think I'd put him through surgery followed by chemo for a tumour.
On balance, I wouldn’t insure the next cat, I'd take a chance but money isn't an issue.