Effective Nov. 17, 2013, Chase Ultimate Rewards cardholders will no longer be able to purchase points. The option to buy points is currently available by calling the service center but is not available online and the maximum number of points you can purchase is 5,000 points per account per month.
Bottom line: Chase Ultimate Rewards points cost 2.5 cents per point and may be worth the expense if you are close to a desired award or planning to redeem for an award where each point is worth more than that. The Points Guy runs through some possible scenarios where purchasing points from Ultimate Rewards makes sense when transferring those points to British Airways, Hyatt and United at http://insideflyerus.wpengine.com/link/?9552