Early A body Car

My 13 year old son is so attached to the 1964 Dart GT. So I think this will be what I am putting at the top of the list. We found one done for $23,000. It is also a radio delete car like my totaled car and comes with a 273 V8. I will need to figure out how to tell the difference among V-8 blocks and check the manufacture dates, my previous car was a slant 6. I think the asking price is a little high since a concourse car comes out at $21,800 on the Hagerty price tool. I did notice a few odds and ends like the chrome missing on the armrest bases. The car should be flawless at that price. The price should be between $16,300 and $21,800. So, I will try to negotiate