Based on pics alone, I'd have to agree, 4.5K-7K depending on part of the country. BUT, if the city is selling it AND they are asking you what it's worth... sounds like an invitation to low-ball. I'm with Myoldtruck on the offer price, but I might have $2300 in my pocket rather than $300 if you really want it. If you offer $2700, they may think the are swindling you if they counter off at $3700.
Sounds like a good opportunity. I'd want to know which 4-speed is in it - since the engine has been changed out. I'm guessing a car 4-speed judging by stick position. Personally, I'd start at $2000 and see what happens - just have cash for your personal limit handy.