it is paid from your gross salary before all deductions, therefore you have tax relief at your highest rate on it.
How much you pay depends on the occupation and the average age of those joining the scheme. Premium is also dependent on when you have the PHI kick in, after 1 month, 3, 6 or 12 months. The longer the lead in period, the lower the premium.
It is also dependent on whether it is to provide any other benefits, such as paying pension contributions etc.
Not possible to give you the exact price