PenutBrittle: I can tell you right now it won't go any lower in the Holiday sale. This is the first time it's been lowered by 66%, and even that took a lot time to get to.
If you're waiting for a 75% off sale, I'd bet you almost anything you'll be waiting another three months at least. Not that there's anything wrong with waiting, but don't get your hopes up.
Metro09: Worst comes to worst I'm sure it'll at least be 67% off again. Anyway, as I said, I'm not dying to play it. I followed the game since about a year prior to it's launch and was ultimately underwhelmed by what they actually produced: an isometric hack and slash of Braid, :Limbo, etc. I wouldn't be surprised if it were 75% off. From a sales standpoint they're probably getting the vast majority of people who would buy at the $5 price point during the daily so the next logical step is to go down to $3.75 to grab even more people.
I played through these 3 games and I think each is a great game worth it's full price but if I had to choose only one I'd say Bastion is easily the best of the pack. In general it really has nothing in common with Braid except the developers are indies and maybe arguably it has it's own visual style.
So compare with the other two games Bastion
* is a much bigger/longer game
* is a lot more rewarding because all the new weapons, upgrades and attacks you earn durin the game
* is the most polished of these 3 games
* has by far the best soundtrack with a pretty unique style and feeling and it's a fantastic match for the game. Honestly in some way it felt a bit like in the good old days when we (well those of use old enough ;)) played C64 games because of the great music from Hubbard, Galway and the like :-))