Fix order of cost validations to properly show error for character data.

lib/pages/expense.dart

@@ -289,15 +289,15 @@ class _ExpenseInputDialogState extends State<ExpenseInputDialog> {
                           if (value == null || value.isEmpty) {
                             return "${Expense.amountText} must be provided.";
                           }
+                          if (double.tryParse(value) == null) {
+                            return "${Expense.amountText} must be a valid number.";
+                          }
                           if (double.parse(value) < 0) {
                             return "Please use the Income page rather than having negative expenses.";
                           }
                           if (double.parse(value) < 0.01) {
                             return "${Expense.amountText} must be one hundreth (0.01) or higher.";
                           }
-                          if (double.tryParse(value) == null) {
-                            return "${Expense.amountText} must be a valid number.";
-                          }
                           return null;
                         },
                         onSaved: (value) {