OK, so I sat down and worked out some scenarios based on the projected drops from this site, and from what I see, you don’t need to sweat about points all that much. In fact, I’m actually somewhat regretting buying any of the Guda-Os since they don’t help at all with shop currency, and from what I see, I’ll be swimming in more points than I’ll know what to do with in the end.
So, here’s the math. If you’re new/F2P, then let’s just form your daily points farming team with a Support Okita (with even just a 30% Guda-O), Oda, and 4 of the 20% servants, and no Guda-O CEs at all on your own. So, that’s just a 270% bonus. But if you do all the dailies with this team, you will end up with 831,020 pts. If all you care about is NP5 Oda, you only need 1 mil, so you’re only 170k pts away.
But let’s say you’re greedy and want to go for the whole 1.5 mil reward level. If you do Raurava, Tapana, and Avici at just a 130% bonus (Okita w/30% CE) from the point they unlock, and even just use natural regen, my calculations say you should get 660k pts, which puts you less than 6k pts away–and I didn’t even count quests before Raurava so you’ve probably already got them.
On the other hand, buying out the skulls and all of the mats is another thing altogether. Since I didn’t pull heavily on this banner, all I have is +2 for the bronze, and nothing for gold and silver. I’ll have to rely on friends with MLB bonus CEs to shorten my grind. I’m going to skip almost all of the bronze items except for the skull (FYI, it looks to me the gold embers probably come at close to the normal AP cost of just doing dailies), which means I only need 200. I’m targeting 2400 out of the 3600 for the silver shop, and 4500 out of the 5400 for the gold shop. To do that, I’ll need to use apples for about 1300 AP’s worth (which is about 10 apples for me).
Based on my math, it looks like I would need a total of +5 bonus for gold and silver drops to buy out as much of the shops as I am doing. Note that since I’m skipping almost all of the bronze shop, anyone who wanted more embers or Fous would have to grind over and above what I’m doing.
That said, there’s a lot of math in my spreadsheets, so it’s always possible I screwed something up. So don’t take this as gospel :)