Rinbin quests are usually followed up by good rewards. You could get one or several "bad" rewards and then at the end you get a great one. Not for all of the Rinbin ones, but for the majority of them definitely. So personally I'd advise against aborting them.
It can be worth it when you have a hard time getting certain goods. It is a gamble but you can end up with nice goods and better rewards. I personally do them when you have plenty of supplies and coins. I do them regularly.