Well, releasing a brand new game in a pay what you want model is pretty good. You can pay as low as you want and get Botanicula (plus 2 other great games you may or may not have) wich is currently $10 at GOG.
I love point & click adventures and somehow I didn't have Samarost 2 yet. So this was a no brainer for me. I've already played Windowsill and probably won't watch Kooky so $5 was fair enough.
Also there was a lot talk about Machinarium recently, specially since Tim Schafer brought it up on their Kickstarter, so there might be more people interested in it, and that is always a good thing.
I don't get why people get so angry when games they already own go on sale, it's still a damn good sale. This is a developer sale and it makes sense there are repeats, specially since they have only 4 games published (and one is free)