I have been thinking about that a lot lately.
Yep. An older classic will outlast two newer cars that cost 60k plus each nowdays. Well worth the 20k investment.
A comparison would be investing in cast iron pans rather than wasting money on cheap aluminium pans. You are going to go through a lot of those cheap pans before you will wear out a cast iron pan.
And depending on make, year, and model not only will they hold their value, they can actually increase in value. You can sell it after using it 20 years and actually make a profit because of the demand for classic cars.