I'm not a business person so I don't know how insane this might sound, but would your best bet perhaps be to reach out to your competitors and other businesses

I'm not a business person so I don't know how insane this might sound, but would your best bet perhaps be to reach out to your competitors and other businesses you think are in the same situation and propose some sort of shared software house to replace the 3rd party solution? It seems rather expensive for a 200 person company to start it's own software division just for internal applications.