I am looking to buy a toyota v6 camry.. seller is saying ...

Hello and thank you for using JustAnswer. My name is \*\*\*\*\* \*\*\*\*\* I will do my best to assist you. During this conversation you will be given an automated offer for a phone call. You may accept or decline that offer.I don’t personally offer this service so if you take this another tech may call. I’m sorry that you’re having trouble with your vehicle. I will do my best to help you resolve them. Please understand that I do not know your knowledge or capabilities so I may need to ask questions to find out basic information to help solve your specific problem. That could be as simple as a sensor or as serious as a computer module, you will need to have a diagnostics done to see what the problem is, I also suggest taking the vehicle to your local mechanic and having a inspections done to see if there are other issues, I would never trust the seller with anything they say.

How much would it cost for serious problem?

Right at 500