For what it's worth...I paid:
~$10,500 for a 2005 SSB 6 speed limited roadster with 22,800 miles in April 2016
~$13,500 for a 2005 SRT6 roadster with 20,800 miles in December 2016

I also, called on a 2005 limited roadster with 55,000 miles (automatic) that sold for $6900 (previously owned by a doctor who's kids couldn't drive a manual).

You might find better deals than $6500...but than again you should assess the maintenance and any repairs you may have to do. There are some salvage places selling ones that need several thousand in repairs for $4000.

Searching Cargurus....Coupe/Coupe Limited with less than 60K miles are selling for 7-9K range. Sounds like a good deal at $6500 if well maintained.