Click on the tab symbol at the left hand end of the ruler until it changes
to a Decimal Tab (Upside down T with a dot) then select the column into
which you want to enter the prices and left click on the ruler at the
location where you want to have the decimal point.  The paragraph formatting
in that column needs to be left aligned and you can adjust the location of
the tab stop more precisely by holding down the Alt key while you click and
drag on the tab stop on the ruler.