That's 2/3 of the money being development costs. Let's guess Roberts has 100 Mio -> 66 Mio. -> after fees etc. 50 Mio. are spent for the development, the rest is pure marketing (I guess it's a lot less marketing costs). Elite Dangerous had 2.440.707 $. Let's round that down after fees etc. to 2 Mio. They had 2 Mio to develop Elite Dangerous.
We don't know how much money Elite: Dangerous cost. Certainly more than 2 Million. Remember that Darklands cost 1 Million in 1992. The podcast mentions that Star Citizen has external investors as well.
Why shouldn't it be possible for Roberts to develop a similar game with attached fps part for twenty times as much money? He isn't even developing everything in the US I think which could help reducing costs even more.
I don't think I can convince you if the detailed numbers given by Teut Weidemann for several projects (including cost, Number of developers,...) can't.
And you don't just have an "attached fps" part. Each AAA FPS released in the past years had larger budgets than all of Star Citizen.
For a space game you need spaceships and backdrops. That is pretty cheap.
For an FPS you need assets, assets, assets. An FPS is more expensive to develop than a space game.
And to combine the two, you don't just combine the cost, you need a lot more. Just one example. When you are running around in FPS a capital ship, and it gets hit by a missile, you need to take damage from the debris, the entire level geometry of the FPS part must collapse accordingly, you need people to get sucked out into outer space, or being unable to breath, unless they have an emergency oxygen kit. All of this is stuff that normal FPSes, which cost more, don't do.
(Derek Smarts games are actually the only existing games that do all of this, but in text mode. I.e. if you assign a guy who is in his quarters to fighter duty, he will start walking to the bay. If the part of the ship he's currently walking gets heavily damaged he might get killed or end up in sick bay.)
If all of this is as easy as you say, why didn't Chris Roberts manage to release Freelancer? Which didn't even have an FPS part.