Wow, my buddy had that exact problem but then it clicked!

The "try their other stuff now" bit reminds me of my roommate's pasta sauce switch. He got the store brand once and now won't go back, says the big name stuff is too sugary. Makes you rethink what's actually worth the extra cash.

Honestly think we just missed it the first time.

I always figured dividing things was mostly about the cash and rules. Your idea of finding a shared goal first actually makes sense, since it turns fights into teamwork. So yeah, starting with what dad wanted could really smooth things over.