Through September 16, 2016, Hilton is offering a 50% off promotion when purchasing their points. This might be a targeted promotion so you’ll have to sign onto your account to see if you are eligible (or if there is another % discount you were offered). I personally am eligible for the 50% off promo and have never once purchased Hilton points before.
Assuming you are eligible for the 50% promo, this means you are purchasing Hilton points at 0.5 cents per point. This is the exact same offer that was around this past April. This is the best we’ve seen for purchasing Hilton points. They are ultimately selling their points for exactly the same price I’d value a Hilton point at. This is not a price I’d purchase points speculatively at, however, if you do a cost analysis for a certain stay and see you’ll get a better price by purchasing points, then I suggest doing it.
You can purchase a maximum of 80,000 HHonors points before any bonuses per account per calendar year, meaning you can max out the promotion for a total of $400. You can purchase points here.