Just found a 1973 with only 30,000 original miles on it-all original and runs incredible.
If I posted it on EBay-what do you think value is in US dollars?

Well you wont be retiring from the proceeds, so if its as good as you say you should be keeping it.

I'm retired from other proceeds! What value do you think?

Couple of grand,maybe a bit more maybe a bit less,

Hard to say as I am only guessing what country your in or if the car is a sedan , coupe or ute.

Post a picture of it,someone here may want be able to give it a good home if your that desperate to turn it into cash.

And as always a car is only worth what someone is willing to pay for it.

In USA $2500-$4000
In Aus $2500-$4500

30,000mi means nothing, if the interior is tatty and the doors/sills are full of rust. Engine/mechanical health is not as important. although if it was mechanically poor, I'd question the milage.

To sell a low mile "old" car, you really need all of the reciepts since new.