We'll know how well LoS2 fared when we see Konami's next project. If it's a LoS game, in name or style, we can figure LoS2 at least kept execs satiated. If it's something else entirely, I'd imagine that it didn't do well enough to keep execs happy.
Not entirely true. They can decide to continue the game simply based on the first game numbers and try to make a new game more like that one, which sold well. Or even another reason altogether... it's their call.
VGChartz are completely unreliable. There's nothing right there, they don't get the data from the stores, how the hell they know the numbers? They even admit themselves they simply take the numbers from their asses.
They update them when some information from NPD (who actually HAVE data from stores) or from the game company itself, but it's still a pretty shitty place to get numbers from.
In Neogaf, they posted some estimatives for LoS2 and it was a disaster in terms of sales. Europe was the same thing. And these big games sales are, usually, pretty frontloaded (unless you're Call of Duty, Pokemon, Battlefield, Fifa, etc). But since we don't know the budget, we don't really know if it was good enough for them to make a profit.
But I doubt this game budget was low, at all.