Some guy off craigslist is selling me his silverface Princeton Reverb for $400 today. What are somethings that can point me to the value of the guitar amp? He says it works, but he just needs the cash. I'm meeting him at guitar center. Here are some pics. http://imgur.com/e59eOoT,ffT8P9V,Pz3qeX7,CmwGECa It looks really dirty, but nothing simple green can't fix.