It's hard to compare a 2.3-16 to a 3 or 400E, different birds altogether. Depends what you're looking to get out of a car. The 2.3-16 offers a unique driving experience, and I believe the factory 0-60 claim was more toward 7.4 or so.
Your more recently found car for sale is tough to judge just knowing year and price. Like yhliem mentioned, it's not the mileage, it's the condition / history.
Email me if you'd like, I'm in CT and am reluctantly selling my '87 2.3-16. The ad is under my user name here in "Classifieds" for reference.
Good luck in your hunt / decision making...