How to Redesign

I ran into a problem not dissimilar to this when doing freelance programming on a hacked together VBA project for score tabulation. I would recommend a redesign in at least VB.net (as he wrote some custom VB libraries that he was hesitant to rewrite).

In the end, even after I showed a spreadsheet of my billable hours spent fixing ten year old bugs, he'd rather have me work a hundred hours on a familiar task then risk losing the interface, and userbase he accumulated over the years.

But hey, in the end, he was the one writing the checks, right?