Please check your coin again and post a new, separate question.
A coin with the denomination "2 new pence" would be a British decimal 2-penny coin minted from 1971 to 1981.
A coin with $5 would be from one of the many countries that use some variety of dollars as their currency but it could not be from Britain because the UK's currency is pounds sterling and not dollars.
The only dollar coins issued in 1980 were made of cupro-nickel, not silver. They're only worth face value.
less than a dollar.
Five Pence GBP in 1980 had the purchasing power of about £0.14 GBP today. NOTE - This historical conversion is the result of many calculations and considerations by a purpose designed program for which I can take no credit. The resulting answer should only be regarded as an approximation.
Around $80 USD
At todays value, I think it is about .055 cents. To start with its not a 5 dollar Mexican peso. Its a 5 peso coin which is absolete in Mexico today. Only value is its composition if silver could be worth as much as10 dollars.if not a few cents.
1980 would make it a Susan B. Anthony dollar, and it's still worth one dollar.
1.00
1 dollar
The only dollar coins issued in 1980 were made of cupro-nickel, not silver. They're only worth face value.
No. A crown in British coinage was worth 60 old pence, or 5 shillings, or 1/4 of a pound.
It's still worth one dollar.
$1 in 1980 was worth $2.61 in today's money.
It's still worth 50 cents.
$1.00 in 1980 had the same buying power as $3.08 in 2016.
There are some excellent images of decimal UK coins at the Related Link below
The 1980 $20 bill featuring the Mayan culture is known as the "Mayan Sun God" note. In circulated condition, it is typically worth face value or slightly more to collectors. In uncirculated condition or with any unique characteristics, it may be worth more to collectors.
It may be worth about 40 dollars depending on the quality of the picture.