It's all part of having animals. If you intend to call a vet for every little thing then you don't need a kit but, personally, I prefer to be able to do some of the vet work myself. The vets know it's not good when we call for an emergency.
Yeah, vets do cost an awful lot. You might surprise yourself what you are able to do without being freaked out at the time. Looking back is when you might be freaked out, once the adreliane rush from the emergency wears off.