Cost of living in Karlsruhe (Germany) is 26% cheaper than in Amsterdam (Netherlands)
This comparison is lacking data. It provides a decent comparison, but it is not yet reliable. It is based on 1,421 prices entered by 335 different people.
For example, to keep the same standard of living that would require €5,300 in Amsterdam you would need to make just about €3,900 in Karlsruhe.