I have sold more than one Neptune in the last 5 years. First one under 2k the second over 2k.
Two things to consider w this title:
Do you like the game? If so, who cares if it’s $3,500 if you’re going to keep it for a long time. It’s pretty damn rare. You’ll get your money out of it if it’s not for investment.
Have you played it? It’s one of those titles that people either love or hate it. I appreciated it the second time around that I owned it and even then others that played it didn’t care for it.
At the end of the day, if condition is fair or above bite the bullet and buy it. YOLO.