How can I map multiple fields to one 'parent' field?
See this example post on Select lists for content types:
How to have CCK &quot;Select list&quot; field on my content type?

you would just make the values for the list option as (value | display text):


500 | $500 - 5br/4ba
400 | $400 - 4br/3ba
350 | $350 - 4br/2ba
... 6 more options of whatever conditions ...
 25 | $25 - you sleep in the closet


This price field could allow up to 10 values if that's your limit.

Since the keys (values) of the prices are integers. You could SUM or Aggregate the values using Views if needed.