TABLE price
user_id b01 b02 b03 b04 b05 b06 b07 b08 b09 MP01 21 32 12 34 56 26 21 21 26 MO11
you can use the LEAST function, as in:
select least(b01,b02,b03,b04,b05,b06,b07,b08,b09) from price where user_id = 'MP01'
http://dev.mysql.com/doc/refman/5.0/en/comparison-operators.html#function_least