Kerbal Space Program

No.......

No, it likely won't. It's a early access game. Those don't do -75%

Yes

Next Summer Sale.

this will be the cheapest you will get it

Dont hesistate - buy it while its this price! I got it for full price and don't regret - such a good time waster!

Probably won't be lower than this, but 1 thing to note - from my personal experience, there's not much to do right now.

I somehow managed to succeed in reaching the moon my first time, and after that everything else is pretty much the same thing.