This car is listed with an asking price of $23,500. As with most cars for sale, you can probably negotiate downward from there.
I wouldn't be quick to say "don't buy it" unless I understand what your objectives are. Here's what I mean by that. If you are looking to buy an NSX in the low twenties, it's not going to be a great example. There will be serious flaws - very high mileage, title problems, accident history (with repairs done poorly), major repairs needed, etc. You'll have to live with those flaws, and/or put a lot of money into it to upgrade it to decent condition. You probably already knew this.
So... it depends on what you're considering. Maybe you're looking for an NSX that you want to buy cheap so you can gut it and turn it into a race car. This might be the perfect car for that! But if you're looking for an NSX that you can drive frequently and reliably without spending a huge amount of money for upkeep, this isn't the one. In the upper twenties, which is not that much more than this car, you can get a decent (not perfect, but decent) early NSX with average mileage, and it will be a far better value. If you can't afford to spend upper twenties (with several thousand dollars in the bank as a contingency for repairs) for a decent NSX, then you really shouldn't be buying a cheap crappy one, either.