Apart from the fact this is far from the last narrow body made (e.g. 9410 is a 1987 narrow body GTS), I concur that you would be paying a premium for the history associated with this car, in fact at the advertised price of $249,000 I think it has to be the most expensive narrow body car ever!
You are much better off finding a great condition for less than $100K and spending a few dollars to make it the way you want. If you particularly want a late model 9000 series car there's a 1985 GTS narrow body on Hemmings for $95K, I have tried to get the seller to send more photos as I was interested, to no avail, maybe you'll have more luck!
Julian