It returned Hilton SF Airport Bayfront at $93 for a room with either 1 or 2 beds. In the Hilton app, I get the same hotel for the same night at $87 for a room with 1 king size bed or 2 double size beds.

Then I was able to search for Hilton SF downtown in Hotel Tonight and find the Financial District one, which was available for the night of Fri Nov 27 for one night. Hotel Tonight had a price of $152 for the following room:

“The hotel will assign room at check in and it will fit 2 adults”

The Hilton app showed the financial district hotel available on Tue Nov 24 (which the hotel tonight app showed as not available) for $95, and for Fri nov 27, the Hilton app shows 1 king bed or 2 double size beds at $159.

So it looks like you’re right for some nights for some hotels, except they don’t let you confirm a room type on Hotel Tonight. I wonder how this squares with Hilton’s best price guarantee:

https://hiltonworldwide3.hilton.com/en/price-match-guarantee...

Looks like they’re trying to engage in some price discrimination. I would call the hotel front desk and tell them, I can pay the cheaper hotel tonight price, and you get 85% of that (hotel tonight pays the hotel 85% of the price you pay hotel tonight), or the hotel can sell to you directly for 10% off the hotel tonight price and end up making 5% more and see what they say.

It’s also possible the franchisor is violating their franchise agreement by letting hotel tonight sell for cheaper than Hilton’s website, so you might be able to get an even bigger discount by filing a complaint with Hilton.