Two options exist depending on how you need this to work. both approaches require the same relationship using your value list formatted field as a key linking it to the table where you store the data for your value list.
TableOccurrence1:: DropDownField = TableOccurrence2::Column1Field
Simply use the field tool to add the TableOccurrence2::Column2Field to your layout next to your drop down field. When you select an item from this list, the matching value in this field automatically appears. This is the best approach if you want any changes to the data in the value list table to automatically appear on your layout.
Since this is an item's price, it's possible that you don't want existing records to show a change in price everytime you change the prices in your value list table. In this case, you define a field in the TableOccurrence1 table and use the Lookup feature found in the field's auto-enter options to copy the number from your value list table.