Apple recommends for all apps with automatic sync to store the database file on the following path:
~/Library/Containers/com.syniumsoftware.iFinance4/Data/Library/Application Support/iFinance/iFinance 4/
You can access the data file and create a backup in a different location. However, do not remove the file from the original location. iFinance will always look for the file in this location and if it isn’t there then iFinance will not be able to access it.