Is $1,000 to replace the gas valve on a water heater a fair price?

My water heater, manufactured in May 2018, has been shutting off or releasing its pressure valve due to overheating for about a year. A company diagnosed it, suggesting the flame is overshooting and needs a new gas valve, which aligns with the 'gas control & valve failure' flash code (seven times). I'm uncomfortable doing this as a DIY project since it's a gas water heater. I believe it should still have life left. I'm not the original purchaser and was told the warranty only follows the original owner. Sometimes the water gets extremely hot during showers, indicating the pressure valve is about to release, which triggers my water leak sensor. There is no expansion tank.