I think that you miss a point in the word original: You have to present original research, not necessarily original result. If you found a cheaper method than anyone before, the result is obviously original, even if you didn't find out anything new.
Example from other sciences: In maths, a new proof of an old theorem is original. In CS, a new algorithm which is just 10% faster than an old one is original. In medicine, a new treatment for the same disease is original. And so on and so forth.
As well, even if your result is not better than the previous ones (slower algorithm, more expensive method), it can of course be original. It's just more questionable whether it's useful, sometimes it is, but you have to be quite convincing usually.