Just because you have the misfortune of living where salt is used there is no reason for you to accept rust as fact of life. Think about how much interest your car would generate in GA or TX. The US has 48 states and at least 20 are totally salt-free. If you want an older car for project purposes find a southern car and spend the 2K or what ever you'll need to get it to NY. I can assure you that no money in the world will improve that car to southern specs. Blasting the rust (assuming you would be willing to disassemble enough of the car for that) and refinishing will not be as durable the factory applied finish of an unrusted car.
Besides, then you could start driving your new car in the salt reducing its value and raising the value of those remaining that have not and do not get routinely exposed.