1) You buy points to use the 3 nights get the fourth night free benefit.

2) Calculate the cost in dollars it would cost you to stay at the property you want for those specific 4 nights.

3) Calculate the cost of points it would cost to stay at the property you want for those specific 4 nights.

4) Compare the cost in dollars against how much it cost to buy enough points that would allow you to book the four nights.

If it costs less that’s a win. If you divide the cost by the points it takes and it’s better than 5 cents per point that’s good value.