**in Korea, the price of a lower apartment is more cheaper than a high-rise apartment.(higher apartment)

In Korea, the price of a lower apartment is cheaper than a high-rise apartment.

OR 

 In Korea, the price of a lower apartment is more cheap than a high-rise apartment.

note: if you are going to use MORE in a comparative form, your adjective must be in positive form. If you say MORE CHEAPER it's wrong because its redundant. It should be CHEAPER or MORE CHEAP.

**i would live in a high rise(skyscraper) apartment building. because it affords(has) such a nice view.

 I'd live in a skyscraper apartment building because it has such a nice view.

OR

 I'd live in a skyscraper apartment building because it affords such a nice overlooking view.