Seriously, it's either this & DLC or XV-2. Take your pick. I for one don't want to be waiting until 2020 for FFXVI.
Back in the day Final Fantasy games could be made with 30 people. Now it takes 300 and a significantly larger budget and development schedule to remain as a AAA competitor in today's landscape. We're still paying $60 for the games like we did back then. It's not hard to figure out how reality works.
Final Fantasy's been AAA in modern terms since VII, to be fair. Heck, FFVII practically invented AAA with its hundred-man dev team, $45mil development budget, staggeringly-high marketing budget, and Hollywood-sourced VFX talent. Adjusting FFVII's price for inflation would get us to ~$66 million, which is almost certainly lower than what XV cost but not necessarily by the amount that a lot of people assume (Tabata expressly denied that the game cost anywhere near the $140mil required for games like GTAV or Destiny.) My guess is that we're dealing with an $80-90mil game at an entry point of $60 rather than $40.
The real issue with FFXV is that... well, okay, there are a few issues:
1) Squenix can't make AAA games at anywhere near the rate as they did in 1997, monetary costs aside, so they need something to fill in the gaps.
2) Console gaming is struggling to draw in the younger market that Squenix wants because kids grow up playing mobile games nowadays and aren't necessarily interested in learning to cope with the extra complication without proper motivation.
3) Gamers expect their games to provide content on an extended basis instead of moving on to a new game when they're done, which costs more money beyond the initial development costs.
4) Big games are much, much bigger nowadays than they were in FFVII's day, and Squenix wants to do everything it can to get a piece of that pie.
Changing subjects to the trailer, it feels a lot more like something intended for gaming enthusiast sites than a general purpose TV spot. Kudos to them for sticking to real gameplay, though (even if they should have made sure the HUD was off in all of their scenes) -- they certainly have enough mindblowing moments that they don't actually need CG to be impressive.