Could you show a graph of how the response “falls apart”? That would be helpful for understanding so we can troubleshoot that. You can definitely get 25-35hz for that price point, it just depends on what quality of driver you want, enclosure volume and shape limitations (we already have this, but what manufacturing/tooling abilities do you have to your disposal?), needed SPL, how much power can you provide. Etc, etc. Those are the kinds of details that need to be considered.