I think it is a great tool you would quickly grow out of. If you're paying attention to the front sight as you dry fire, you will know what position it was in when the sear broke. I would try the regular ol' dry fire consistently for a month and if you see no improvement, it might be time to spend the money. The key there is consistently.
If you can't see where the sight was when the sear broke, slow the trigger pull down until you do.