i dont think £30 is that much of a rip off. Such a small leg makes a vets job even harder. Putting a plaster cast on a human leg can be tricky and stressful for a doctor let alone a vet. Also, that £30 would have included an injection of pain relief.
Getting quotes is a good idea, also check to see how experienced a vet is with your pet, some specialise is certain animals over others