In my opinion, no that is not a good deal. You didn't state that it was anything special, IE a redwood special, with that, your price range is going to be "standard".
I try to keep up with market values of our beauties. And the last X I saw with no miles, was around $11000 range. And it was exceptional.
I'm assuming 0 miles or very close to it.
An X today with all upgrades done (roughly $3000 if hired out) and reasonable miles for 20+ years old bike, are running in the 5-7000$ range if in good shape. Reasonable miles to me would be anything between 10000 - 50000.
Its not uncommon to see X's with more miles, and being very nice, but with those miles, and not knowing the owner or bike, the price comes down. As always there will be exceptions.
Abused or not maintained?... 3-4$.
Exceptional condition up to 10.
If this is the case, it's been sitting over 20 years.
I wouldn't even attempt to start it, without pulling tank and fuel system off, and thoroughly cleaning and most likely relining tank. It may very well start and run even if this isn't done, but I promise you it will bite you soon, and most likely in the wrong place and time.
Tires will look like new, but will be junk.
Obviously an oil change would be in order also.
My X has just turned 50000, its a 99, standard black. Nothing exceptional. I feel very nice condition, and runs well. Most likely not worth more than $5000 if I was lucky. But I'd never sell it at this time for any kind of money. It just grabs my heart strings. All of the upgrades are done on 525, and it took me most of the 20 years to get them all done on my budget, and I did them.
There is a substantial number of us in the community, that really want the market numbers to go up. They want their stable to be worth more, than the last 10 years. Not as an investment, but I suspect more for the collectability values. I like that idea, but it would probably knock me out of the X world market place completely. My budget is pretty small.
It does mess with your head in public talking to someone who doesn't know anything about super Xs, and you tell them you can find them a very nice rider that looks great for around $7000 or less.
Hope this helps with your decision.
Bruce