First, Unit Price sounds like one number. But if you want to enter multiple
lines in a cell, you can either allow excel to determine the breaking point (you
turn on wrap text, though). And you could use the format painter for
this--although I think it would be easier just to select the range and
format|cells|alignment tab|check the wrap text box.
But you can have more control over line breaks by using an alt-enter in your
cell. Excel is usually smart enough to recognize your entry and turn on wrap
text, but just in case it doesn't, it's still under format|Cells...
But be aware if you put numbers separated with an alt-enter in a cell, then that
cell isn't a number anymore. It's text. You could extract the two values, but
it makes life a little more difficult for common formulas.
I'd do my best to avoid doing this, if I were you.