There's a few things to Unpack there. For starters, he was asking $18k like 5 minutes ago. He dropped to $14000 which we can agree is a good price considering what most people are asking for these cars now. Second, His car is also not perfect. It has 114,000 miles, Duct taped bumper fillers, moon roof and so so looking paint. That's without actually looking the car over in person. His ad is vague and lists ZERO issues in the description. Let's assume there are some as my experiences tell me there will be. That car is maxed out at this price level. $14000-15000 is the ceiling on the car.
The car in question is a 55,000 mile car. If you address the engine which looks to be mainly detail and maintenance, replace a few things in the interior and do a strip and dip paint job the car is on a different level. It would be a $55k mile Hard top car. Not a 114000 mile moon roof car. $15,000 is definitely a stretch but a starting point. As I said I wouldn't take less than $10k. There may be a guy with money in the bank that buys it for $10-12k and sends it right to the paint shop to make it a beautiful car.