Oh strange! I'm going to majorly change how some things are bought/sold so those should be fixed in time.
F6 is how much money you have! I need to fix it so it says it as a proper number, so if it says "2" "3"1" it just means you have 231 money.
And yes to delete the save file just type this into file browser:%localappdata%
Then delete the folder Symphony of Soil.