Ideas
I have also been encountering a similar bug moving from one lot in Oasis Springs to another lot in the same world. I move, and regardless of the options on the moving screen or the lot, the game attempts to give me the rosebuds achievement and more money than the game can handle, resulting in it displaying $0. I cannot give or remove money via cheats or typical in-game methods. I tested with and without mods, have repaired the files, emptied the cache, and restarted both my PC and the game.
I have not been able to replicate it in another save, but I am wondering if it has to do with some of the money opportunities available in various packs. The sim this bug is occurring with accepted the inheritance money from the Life and Death pack and completed the 7 Wild Dates game successfully from Lovestruck.
Update: the value it is attempting to display is 18,446,744,073,709,551,266 simoleans. I should have 4,444 after the move