Table schema:
CREATE TABLE table_name_46 (issue_price VARCHAR, mintage VARCHAR, artist VARCHAR, year VARCHAR)

Question: What is the issue price of a Year 2000 coin by artist John Mardon of the Included in Steam Buggy mintage.
SQL: SELECT issue_price FROM table_name_46 WHERE artist = "john mardon" AND year = 2000 AND mintage = "included in steam buggy"