Which is cheaper for and most practicable in Nigeria: Democracy or Impositocracy?
HINTS: (A) Democracy is the government by the people, for the people and of the people.
(B) Impositocracy, according to scholars, is the latest brand of government where the aggregate franchise of the voting masses in choosing their leader is positively irrelevant.

You may wish to support your answers with evidence and how each system works in any society.

The only cheaper and practical reality of Nigeria is disintegration

First of all, you need to have deep knowledge about Nigeria in order to profer solutions for her.

First of all, Nigeria was not meant to exist. Atleast not as a country because she is just a business enterprise/company for Britain. No matter how you put it, Nigeria is a business venture of Britain and just like other businesses, she is expected to yield profit for her owner (Britain).

So the first thing to do is for those exploited under the name of the company called Nigeria to free themselves, afyrt that will one start looking for the best government to run their respective nations.

For example, Bini kingdom don't have any business with what you proposed. After their freedom, they will revert back to their monarchy. Yorubas will form a federation like before, Hausa will go back to their religious motivated Government in the form of Sultanate with various autonomous emirates and Igbo, a highly decentralised Republic.