It can be worth in uncirculated condition up to 4 pounds but in circulated condition it may fetch 2.50 - 2.00 pound
Such a coin does not exist. The British One Pound coin was first issued in 1983.
There was no 1811 British Sovereign or One Pound coin minted.
1 pound
Please check your coin. You possibly refer to the 1986 commemorative Two Pound coin.
There was no British 1901 Two Pound or Double Sovereign coin produced.
Such a coin does not exist. The English have never produced a 4 Pound coin.
£5
72.90
Face value.
The first gold Fifty Pound coin issued by the Royal Mint was in 1987.
As I type this the value of 1 pound of gold is $18,040.00
£2.00