It is not possible for Greeks to take significantly less pay than Germans, because they still need to buy the same food and shelter in order to live, and the prices of those items are denominated in euros and set in the eurozone. Normally, in a developing country, the low wages are offset by the low cost of staples in the local economy (which themselves are offset by the general risk of death being higher in a developing country). But that's not possible here.
I feel that people are still not understanding the underlying structure here. We understand that the euro zone is a mechanism for Germany to export cheap commodities without destroying its balance of trade. But there are lots of things that can be commodities. For example, labor is a commodity. Companies need to buy labor to produce goods. Having a capital advantage is usually understood as meaning that goods are cheaper to make -- but another way of understanding it is that, with better capital, companies don't need to buy as much labor per unit of goods. That means that the demand for labor is lower, which means that the value of labor falls.
Germany isn't just exporting cheap electronics to the rest of the euro zone -- it's exporting cheap labor, created by industrialization and automation, to the rest of the euro zone. (And of course its business-friendly policies are part of the same story.)
Now do you understand why Spain and Greece are running 25% unemployment?