No person will, be allowed to purchase the Homestead of any occupant of a run held with the permission of Government, until the offer of purchasing such homestead shall have been made to the occupant of the run at the price of either Ten Shillings per acre, or Five Shillings per acre, according to the quality of the land, as the same shall be certified by the Commissioner of Crown Lands. The occupant of the run will in such case be allowed to exercise the right of purchasing his homestead at such fixed price over an extent of land varying from ten to eighty acres, at his discretion. But the Government reserves to itself the power of requiring the occupant to exercise this right at any time after one month's notice, although no person should have applied to purchase the land.