The pilot noticed that the engine turbine temperature had increased to close to its maximum limit and prepared to make a precautionary landing. During the approach the indication returned to normal, so he decided to continue the short distance to his destination. As the helicopter climbed away, the engine failed. The pilot carried out a forced landing during which the tail boom struck the ground. He candidly commented that, on reflection, it would have been better to continue with the precautionary landing, rather than having to attempt a forced landing without power from low altitude.