That is not an official govt issue coin. It is not legal tender even though it says $50. These for the most part have value based on their silver content. How many were minted...well at least 50 ( based on your serial number) and no more than 9999 based on the number of digits available for numbers. Wish I could give more specifics, but finding info on non-government issue silver rounds can be difficult. My guess is that they minted 10,000 total ( including one numbered 0000)