CREATE TABLE catalog_structure (catalog_level_name VARCHAR(255), catalog_level_number VARCHAR(255)); CREATE TABLE catalog_contents (catalog_level_number VARCHAR(255), price_in_dollars VARCHAR(255))
What is the level name of the cheapest catalog (in USD)?
    
SQL: SELECT t2.catalog_level_name FROM catalog_contents AS t1 JOIN catalog_structure AS t2 ON t1.catalog_level_number = t2.catalog_level_number ORDER BY t1.price_in_dollars LIMIT 1