I missed the bus back to Copenhagen

Hello Amgio!
I am at Berlin Hauptbanhof(Central train station) now.
It seems like I should have been on the bus back to Copenhagen already, but why am I here? It's easy--I missed the bus!
I was 15 minutes late when I got to the bus station, and the German bus was obviously more punctual as the Polish bus. On top of that, there were no more seats to Copenhagen today.
I decided to turn this into a good learning point and tried to figure out all my options.
1. stay one more day here, and then take the bus back. But by the time I am in Copenhagen, it will be at least 5 pm and I have to cook dinner for my colleagues tomorrow at 5. Not good.

2. Take the train or fly back
So I hurried to the Central station, munching on my chicken kebab (one of the small stupid reasons that I missed the bus) on the subway and saw a "no eating" sign on top of me when I finished it. The train station lady said that for a second class ticket that arrives at Copenhagen at 00:18 will cost 120 euro. That is about the transportation cost I have spent for the entire trip so far. So I came to this internet spot, checked out the plane ticket. EasyJet flies to Copenhagen and arrives at 8: 55 pm at the cost of 126 Euro. It appeared that at rougly the same price, flying saves me more time.

So I am about to head for Schönefeld aiport now and hopefully no more shit will happen on the way. Although I could have avoided this all together by getting to the bus station earlier, one of the learning point today is to forget all the sunk cost and quickly evalute what options can statisfy your most important parameter--in my case, they are time and ticket cost.