Camry rear cam seal leak

My '00 Camry V6 w/almost 160K has what has been described as a rear cam seal leak. I am told that it will get worse w/time and eventually mess up the timing belt. Timing belt and water pump were last replaced @90K. I have been quoted $1300 to repair. I am reluctant to put more money into the car. Are there any oil additives out there that might bring at least temporary relief?