DeletedUser
I aborted that one for the very same reasons. I still managed to get other diamond-rewarding quests, and so if I were in your position I would abort the quest. However, different quest completion paths may lead to different quests offered. You may have completed/aborted different quests than I have, and so you may or may not get more diamond-rewarding quests later on, or even as many. So it's up to you.