I wanna move to UK on employment visa. How much...

To obtain a work visa in UK, you must obtain a work contract, and then go to the UK Embassy in the country where you reside, and apply for a visa,
The application shall be accompanied by the following documents:
1) Copy of a valid passport for at least six months 
2) Two photographs with the same specifications of passport photo with white background for each
3) booking flight
4) Copy of the contract of employment or letter of employment

For fee You can contact the Embassy through the following link :

British Embassy Abu Dhabi