Hey~
Yes, if I recall correctly gameplay_constants.xtbl is how much "capacity" the money can rack up to before you press Cash button (maybe how many minutes before you earn it too?)
shop_names.xtbl has how much money the property actually earns, alongside the cost of each one.
Both of these in misc_tables, if not maybe da_tables.vpp.
Note all games have a money cap of 20 million.
I assume you already know how to use the menthe-sr-tools for exteacting the files?
Also, welcome to SRM Kamilla!