Hi Noah,
you can compare the two cities by yourself:
Statistic informaton about unemployment in Berlin: ****://tinyurl.***/jky56s6
Statistic informaton about unemployment in Mannheim: ****://tinyurl.***/zvtn3a3
Housing situation is tough in both cities.
Cost of living is cheaper in Mannheim (****://tinyurl.***/jqhocns).
Kind Regards, Jan