I do believe sapphire's economy is better than diamond, so I don't see why you wouldn't go for it. Currently, FNO doesn't have 75 awakens, nor do we know exactly the date they will get it. FNO content takes about 4-5 months to get to us... so no point in stick with 65 awakens when you can dominate much better with 75 purple for the next predictable 5-6 months
Not to mention, we don't even have 75 trials yet and I doubt we would get it within the next few weeks. No 75 trials, no 75 gold, no 75 awakens. So a few weeks of work to dominate for a couple of months... seems like a good deal.