TABLE price
user_id b01 b02 b03 b04 b05 b06 b07 b08 b09 MP01 21 32 12 34 56 26 21 21 26 MO11
Base on your example i think you mean the result is 12. If that is the case you can do
SELECT LEAST(b01, b02, b03, b04, b05, b06, b07, b08, b09) FROM price WHERE user_id = 'MP01'