A while back, I had an interesting though that could be turned into a fun idea, not to say that it could be profitable too. Although Lagos has quite a few second hand stores mainly the property of NGOs as charity shops what Lagos does not have is a more up-market type of second hand facilities, either in furnishings or clothing.
I have no doubt that either of those ideas could be turned into interesting businesses.
With the price of new branded and designer clothes reaching astronomical prices you could buy and sell good clothing for a profit. I am not talking about oriental cheap manufactured goods that fall apart after the first wash. I am talking about branded goods that people could buy at a fraction of the retailing price. You could for example start such a business as a home based business as an exclusive Women's Club.
Still within the second hand market, you could set-up an Internet based Global Bargain website. This would be a website that specializes in designer bargains or designer bargain hunting from around the world.