Its cheaper to buy a well constructed flat in cash than build your own.for instance if u were to buy an old flat in Donholm or Tena and then do some improvements/renovation it would be much cheaper than buyin a plot in the same area and building the flat.
People forget those small small costs which come with construction e.g paying for security during construction,delays caused by lazy workers,travelling expenses to the site,airtime expenses when sourcing for material the list is endless.
My advice to you is u buy a completed flat at a reasonable price and save yourself the husle then renovate it.
Thats how Sir. Henry of homeboyz made it.
you can achive all things through Him(Jesus Christ)
'......to the acknowledgment of the mystery of God, and of the Father, and of Christ; 3 In whom are hid all the treasures of wisdom and knowledge.' Colossians 2:2-3