My cars private party value is $985 ...
If someone is looking for a mint 240 it's going to cost more than the norm, how much more is up to the buyer looking for a great condition 240 such as this. Hell, fox body notchbacks in mint condition, even stock, are going for 10k sometimes and they book for 2-3k.
If you don't like the price, you could let this topic die by not replying and you could stop frustrating yourself with it.