Just noticed this feature when was surfing around the HH website and don't remember seeing it before now (but I could be wrong).
https://www.hiltonhhonors.com/purchasepoints/
I know not everyone will like the USD 12.50 per 1,000 points purchase rate, but it depends what the goal is. When I was looking at staying at Scandic in CPH, found Opportunity level was 15,000 for 3 nights. So, that means someone with zero points could enroll, pay the USD 175.00 and get 3 nights that would normally cost around USD 108.00 per room per night at Scandic Webers in CPH.
And the thing I was happy to see was that you did not have to be a U.S. resident with U.S. credit card and U.S. billing address to purchase the points, which is the way it is with most of the major U.S. airlines.