Table schema:
CREATE TABLE catalog_structure (catalog_level_name VARCHAR, catalog_level_number VARCHAR); CREATE TABLE catalog_contents (catalog_level_number VARCHAR, price_in_dollars VARCHAR)

Question: 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