Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE catalog_structure ( catalog_level_name VARCHAR, catalog_level_number VARCHAR )
TABLE: CREATE TABLE catalog_contents ( catalog_level_number VARCHAR, price_in_dollars VARCHAR )

### Question ###
What is the level name of the cheapest catalog (in USD)?

### Accurate 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