Germans benefit a hell of a lot from being in the Euro Zone and they export one third of their exports to other countries in the euro zone. These countries will not be able to afford anything from Germany if they have to pay for it in D-marks, that's for sure. Who takes up that slack? China? The rest of Asia? America? All these answers are a loud ass NO! They won't.. even if China could afford to pay more for German goods do you think they'll pay that mark up? They'd just as soon bootleg everything they make in Germany and sell it domestically and to the rest of the world for that matter. And with the D-Mark back every other currency gets a lot cheaper further diminishing the German export edge... Once demand for German goods is destroyed it won't come back until they re-enter the EU and get that price advantage back so they'll lose jobs out the ass.
If you add to that the carnage that would follow Germany leaving the EU it looks like the spark that ignites WWIII... The animosity towards Germany would be so high and set off such a protectionist wave of sentiment that hardly if anyone would buy anything made in Germany, and they won't be able to afford it if they wanted to. They don't have a big enough consumer base to take up the slack and history tells us that when things get rough in Europe the guns come out. The only reason they ain't out now is because of the EU. But if Germany leaves the EU the Euro and the EU go to hell and the devil is coming for Germany. The check Germany would have to write would be huge, but it still wouldn't add up to the advantages they get from having a cheap currency or better yet the cost of what follows if they leave.
The only way out of this mess is to CUT THE CHECK.
The sad part is that the people of Germany don't know this and their leaders aren't telling them for whatever reason.. Maybe it's because they would have to admit that it's not German engineering alone that keeps their exports strong but also the fact that the goods are relatively cheap something everyone knows already anyway...
Plain & simple, the death of the Euro is the death of Germany.