I think there is no real solution that people will like. In order for the price of a condo to fall to match the price of a condo in a rural area, there would need to be a huge amount of construction (I think more than most people realize) to increase supply sufficiently to satisfy demand. Doing this would drastically change the lifestyles of the people living there.

I am just speculating, but think of a city New York now, it is already known to have horrible traffic and overcrowded transit. It is also known to have some of the most expensive real estate in the world. In order to become "affordable" you could build tons of high density housing however how much would it cost to take a taxi or eat at a restaurant if you did this? I'm sure many well of people would leave because their quality of life would decrease due to these changes. So you would basically be trying to find a new equilibrium of real estate prices.