Implement a method that safely parses string input for a product price and quantity. Your method should use TryParse to convert the price to a decimal and the quantity to an int, and return a message indicating the result.

• Attempt to parse priceInput as a decimal.
• Attempt to parse quantityInput as an int.
• If both values are invalid, return "Invalid price and quantity input.".
• If only priceInput is invalid, return "Invalid price input.".
• If only quantityInput is invalid, return "Invalid quantity input.".
• If both values are valid, return a message in the format: "Total cost for {quantity} items at {price:C} each is {total:C}.", where {price} is the parsed decimal, {quantity} is the parsed int, and {total} is the product of price and quantity.