Germany is an expensive place to live, and the relatively high taxes of various forms, plus the need to have expensive medical insurance, should be taken into account if you plan to retire there. However, Germany does have double taxation agreements with many countries and if covered by one of these you will not be charged twice on your income when living in Germany.

For expats from many western countries including the UK and US state pensions can generally be paid to them direct in Germany, and they will benefit from any increases in the same way as if they were in their home countries.