Complicated IF/OR formula needed

Hello! I have a messy formula that I need to figure out. I have a list of several options. Most of them require a common formula, but two of them require unique formulas. They all use the same field though, so I gotta figure out how to put them all together.

So let's say that I have Option1 thru Option7. For Option3 thru Option7, I need to return the formula H55*H56. If Option1 is chosen, then I need to use formula (H55*H56)-400. If Option2 is chosen, then I need formula (H55*H56)-500. Also, the results need to roundup (just to keep it really interesting).

Here's the formula that I have so far, which only incorporates Option1 (ignore the IFERROR).

=IFERROR(IF(A55="Option1",ROUNDUP(((H55*H56)-400),0),ROUNDUP((H55*H56),0)),"")

How do I get the Option2 conditions/formula into this? Or do I need to do it completely differently?

Thanks!