Depends on the 2RM in question; there are 4 different types, 7 different mints and 6 different years - prices are for XF-EF in EURO's
Luther Commemorative (1933)
1933 A:27, D:29, E:55, F:35, G:45, J:42
Schiller Commemorative (1934)
1934 F:75
Potsdam mit Datum (1934)
1934 A:10, D:11, E:21, F:13, G:23, J:16
Hindenburg mit Hakenkreuz (1936-1939)
1936 D:13, E:55, G:25, J:120
1937 A:6.50, D:6.50, E:8, F:6.50, G:9, J:8
1938 A:6.50, B:6.50, D:7, E:6.50, F:8, G:7, J:8
1939 A:6.50, B:7, D:6.50, E:50, F:7, G:8, J:7
like all other German coins, price is highly dependant upon Year (Jahr) and Mintmark (Mzz); some combinations are cheap as chips (say 1939J), while coins that only differ only slightly (say 1936J) are worth a whole lot more. As you can tell, the keys are the 1936J (120EUR), 1936E (55EUR), 1939E (50EUR). Similiar are the Luther commemoratives and the Schiller commemorative, although nothing is particularly hard to find in grades upto EF-AU; things get tougher when you want Unc or Proof...