The blatant extortion of Nigerians by the British Immigration Rules

I am very worried by the proposed plan of the UK Government to make citizens ( first time visitors who have been issued 6 months visas ) of selected countries including Nigeria, pay 750,000 Naira ( 3,000 pounds ) deposit to discourage the individuals from overstaying in the UK. Please note that the UK visa fees for Nigerians is the most expensive among other diplomatic missions in Nigeria. 
I am also worried that in no distant time, some other countries will follow in the steps of the British Government and subject well meaning Nigerians to this extortionist game plan. 
I am more worried that our Ministry of Foreign Affairs will continue sitting idly by without taking adequate steps to address this issue and spare us further disregard and disrespect by countries who benefit immensely from Nigeria in many ways.