What's it worth? 1972 Duster \6 All original

I may have an opportunity to get an all original 1972 Duster. This would have original paint and pristine interior. I'm looking at it this afternoon 64K original miles, Arizona car, stripe package sides and rear apron, slant 6 auto. This would go for 10+K if it were a 318/340. What's it worth?? Thanks!