Propane tanks 10 years old, what is best choice ???

Over in NJ the cost to recertification is high, at least by me. So it would be cheaper to get new 30 lb tanks. Next time i go through PA i will get them , much cheaper then costco. And they come full for like 30 bucks cheaper. At least qhen i checked a few months ago. Mine are almost at the 10 year mark. I dont use them much. I dont use the heater or stove inside the TT, just the fridge and to preheat the water. I cook on a seprate 20 lb tank.