Buy Bioshock Infinite now on Steam and get two games exceeding its value for free.
All of the alarm bells.
If BI is junk, then you're not getting them for free, you're paying $60 (or whatever it is where you are) for them. If you were to buy them during sales, they'd be considerably cheaper. If you were to buy them and BI during sales, and wait a while for BI, you could potentially get all three cheaper (especially if you waited for 75% off sales).
I can't imagine why they'd be throwing games at people for pre-ordering unless they were desperate to get people to preorder, and I imagine that could only be because they either spent too much money and need to make it back somehow (and think this will boost revenue), or know that it will get bad reviews and are trying to get people to buy it without waiting for reviews.
That's not really a valid comparison, though. Obviously, if you wait until everything is on sale you get it cheaper. That's kind of the exact opposite of Pre-ordering, where you know you're paying full price in order to play the game as soon as possible.
Getting free games along with the one you're pre-ordering is a perfectly valid bonus from the standpoint that those game decrease the risk involved with pre-ordering.
If your goal is simply to save money, yes, by all means just wait until everything is on sale. If your goal is to play X game as soon as possible, then getting games that are a known quantity in addition to said pre-ordered game simply makes the risk a bit more palatable while increasing the potential reward (2 good games + a potentially awesome pre-ordered game).
Now, that's not to say that the fact that they're throwing two games into this to get you to pre-order isn't a warning sign. I'm just saying that if getting those two games
now at that price is worth it to you
plus the ability to play BI on release day, then it's a good deal even considering the risk of BI being bad.