Honestly curious what part (not regional) of Germany should have directly benefitted in your opinion. I was too young at the time (just finishing school) but in the span of 1-2 years it seemed that all prices were adjusted back to the old value, but we had traded in our money at 2:1. The beers I bought in a pub were 4-5 DM and not soon after it was 3 EUR, that's definitely not due to inflation. The difference was basically so shockingly large that I actively wondered how this would work out in the next years.

You mentioned exports, so maybe "the economy as a whole" or everyone already having their company running. Also I've seen housing prices go sideways in the 00s, but not sure if that's completely unrelated.