That's a steal! I purchased my 89 in April for $5000 with 52000 miles and I thought I got a deal. This is a great site! Read on and learn. There is a multitude of knowledge and some great people who are willing to share it!
At that price it probably doesn't matter much what model it is, but there is a difference between models.. there is the SE, Aspencade and Interstate (from top to bottom).. They will be priced accordingly.. the biggest issue is the reverse since it cannot be added latter.. (I think I have this correct.. someone will correct me if I am wrong)
SE - Sound/Intercom, CB, Reverse all standard
A - Sound/Intercom, CB-Optional, Reverse
I - Sound/Intercom, CB-Optional, No reverse