Keep in mind while you've somehow convinced your self the car is worth that much you'll be the last owner. "typical" Miata rust is a spot on the lower quarter which is just the cancer bubbling to the surface. The rockers are structural on these cars and anyone who bothered to research the cars knows they are worthless at that point because a fix costs north of 1500-2000$. So ignoring all the other valid points the best you can hope for is to get another year out of the car before the rust does it in or the motor pops in which case you have a 500$ part out.

As a data point I sold my NA8 in the same shape with 170k miles for a grand and was lucky to get that.

OP said Civic when all I remember hearing was Camry and a 2001 Altima for $1500. Enjoy your ride. It will be rough.

On what planet do Miatas typically have rust?

The above post is absolutely correct.

That being said if you have a non-winter driven Miata in the f**ked or north-rusty location. They are worth a bundle of gold bars.

I like the road trip idea;

1) Find a car in a non-rust area as designated in the helpful map
2) Find a buddy with a working, moderately reliable vehicle
3) Walk into his room and say "ROAD TRIP!!" in a loud and peremptory tone
4) Enjoy rust free Miata at a reasonable price

Can confirm, that map is pretty dark accurate for the east coast. My NA was from just above it and my NB is from just below it. NAA was a hot mess.

This is an element that is unique to Miatas and other cars that people don't want to drive in the snow. I'd say a good 75% of Miatas in my area have never seen a winter; all three that I looked at before buying mine were summer-only cars. The one I eventually bought barely saw rain. You also get lower miles and less sun damage than southern cars.

When it comes to buying a used winter beater, I'm considering buying my next one on the West Coast and using it as an excuse to road-trip back, even if my parents' old '04 Concorde has been holding up remarkably well rustwise.