Body work and looks are the last thing you should think about when buying an NSR.
Worry more about the engine, frame, suspension, etc. first. Getting body work cleaned up is easy compared to trying to fix a roach of a bike.
As someone pointed out there are two left side fairings, find out if that was an error for the photo, or not. I would save the $500.00 on the paint and take it as is. Also, make sure he has headlights, tail lights, etc. That way you can at least run it when you get it.
Who are you dealing with? If it's some one not on the Forum or email list I would be VERY VERY careful. Don't send money, go do the deal in person. Make a weekend out of it (it's only down in Florida).
The engine could be tired, but at 17000 kilometers on the clocks, I would find out when the last top end was done. The cranks are recommended to be redone at 30000km, so you have some time for that (oh my NSR went out pretty much right at 30000).
When you go to look at the bike do a decent inspection. Pull the pipes, look up the exhaust ports to get an idea on the pistons, cylinders and heads condition.
Check steering head bearings, wheel bearings, etc. On a bike this old your going to expect that you need to do some work, but you need to figure out in your mind just how much and make your own well informed decision.
Make sure it kicks over, runs good and strong and you should be fine.
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Charles Gallant