Getting a list of homes under median value

[Graham K.]

I am building a list in ListSource at the moment and am wondering how you filter for properties under median value. I know I can just look up the median value for a zip code and use the Current Value filter to set the maximum. But it seems that would be inaccurate because median value for 5 bed homes will be much greater than median value for 2 bed homes.

Is there a filter criteria I am missing or is there a better way to do this? Thanks