Star Citizen is notoriously widely considered to be vaporware; I wouldn't really give it as an example of "achievable with time, budget, and limited resources."
Yeah, probably not the greatest example of a lean operation. But the argument was that it's impossible on current hardware according to GP, which I don't think is true.
In regards to Star Citizen being vapourware, my recommendation would be to take a critical look at their timeline and what state the game is currently in and ask if you could really see it going any quicker. It's a controversial project, but I think calling it vapourware is just the industry being dismissive.
They had to build the team from nothing, now 700 people, and they are building two games not one, both are pretty groundbreaking in features and scope. That considered it is actually moving pretty quickly. They have already delivered a bunch of those groundbreaking technical hurdles to players. Of course the whole thing could implode yet, but it's looking good.
They deliver consistent progress reports and updates to the playable alpha, which has enough content for me and friends to play regularly for fun now. Updates every three months is the schedule, plus any in game content events that get run.
