더라니까

I saw it, I told you

It welds the first-hand observation marker onto the insisting ending, so it means I saw it myself and I already said so: I told you this place was expensive; see, that is exactly how it turns out; So Min did have a card, I am telling you. It shows up when the speaker has been proved right or is pushing back against doubt. Without the insistence, the plain report is 더라고.

Register: casual and emphatic