You can do it using Dynamic sql as follows:

--Setting up Sample Data

Create Table Ex

(

ProductId Int,

name Varchar(20),

familyName Varchar(20),

listPrice Int,

price1 Int,

price2 Int,

price3 Int,

price4 Int,

price5 Int

)

Insert Into Ex

Select 1,'Pepsi','Soda',10, 9, 8, 7, 6, 5

Union ALL

Select 2,'Coke','Soda',10, 9, 8, 7, 6, 5

Union ALL

Select 3,'Fanta','Soda',10, 9, 8, 7, 6, 5

Union ALL

Select 4,'7-Up','Soda',10, 9, 8, 7, 6, 5

Union ALL

Select 5,'Pepsi','Soda',10, 9, 8, 7, 6, 5

Union ALL

Select 6,'Marlb','Cigarrettes', 10, 9, 8, 7, 6, 5

Union ALL

Select 7,'Camel','Cigarrettes', 10, 9, 8, 7, 6, 5

Union ALL

Select 8,'7-Up','Soda',10, 9, 8, 7, 6, 5

Union ALL

Select 9,'Pepsi','Soda',10, 9, 8, 7, 6, 5

Union ALL

Select 10, 'Supe','Candies',10, 9, 8, 7, 6, 5

Union ALL

Select 11, 'Sugar','Candies',10, 9, 8, 7, 6, 5

--Query for your requirement

Declare @Soda Varchar(10), @Candies Varchar(10), @Cigarrettes Varchar(10), @sql Varchar(MAX)

Select @Soda = 'price1', @Candies = 'price2', @Cigarrettes = 'NULL'

Select @sql = 'Select ProductId, Name, familyName, (Case When familyName = ''Soda'' Then COALESCE(' + @Soda + ',listPrice)

When familyName = ''Candies'' Then COALESCE(' + @Candies + ',listPrice)

When familyName = ''Cigarrettes'' Then COALESCE(' + @Cigarrettes + ',listPrice)

Else ''''

END) As PriceAssigned

From Ex'

Execute(@sql)

Hope this was what you were looking for.