One of your clients is about to retire, and has two choices for his retirement plan payouts. He can elect to receive a 23 year annuity of 20,000 per year starting at the end of this year, or a lump sum of 251,000 payable immediately. If the client's required return is 7%, how much more valuable is the lump sum compared to the annuity?

Note: The number can be negative!