Hi, I live in Delhi and a person has a NAD 3020A for sale for about 12k, which he is claiming is in excellent condition. Is this a good price for a used NAD?, if not, then what should my offer be, I am probably going to Audition the Amp day after, he is claiming that its never been serviced or opened otherwise. So what do you guys say? I could use a pointer list of what to check.