All, was confirmed in my attitude for this on my just recently completed trip to Italy. Had a long layover at FCO with friends, and, because of numerous past great experiences with the breakfast buffet at the Hilton there, I suggested we eat there and hang out before our flight to Sofia. What a mistake! I don't know what the issue was(and didn't get an explanation from Management) but during the last hour of operation, the staff seemed determined to not replenish the food on the buffet but in clearing areas as fast as the particular food disappeared. Yes, I did complain, yes, there were apologizes, but there was no attempt on to change things-they did, however, did take my HH# and said something(not yet )would happen as a result of my complaints.
I also want to say that this year I(and family) have experienced treatment and buffets in the "Hilton tradition" in Iceland, FCO, Milan,and at JFK that exceeded expectations, and all were priced at €24 or equal to that in the local currency. So, just saying, beware of reviews and check with other sources to make sure service and quality haven't slipped.
It can be a toss to recommend restaurants and hotels for the most part. People have different expectations, appetites, budgets, food likes/dislikes.
In your case though, it seems reasonable that a Hilton Hotel would accommodate a hot and full breakfast; especially when paying that much for it. And, you did state that you had at least one hour before they closed up shop.
I can "see" if peeps came in at 10-minutes before closing time. Then it would not really be economical to fill up the buffet bins. They can offer a made-to-order omelette so food would not really be wasted.
There is probably left over whole, fresh fruit, cereals, yogurts. But, $24 is steep for just those.
Although, my experience with a long weekend package deal at a Hilton property was their complimentary breakfast buffet and "Made To Order" Omelette station was pretty much plentiful. They did not rush out the patrons. They served coffee or extra juice to those who lingered a bit and wanted it. For those who did not have breakfast as part of their stay paid $10. A very good deal for all you can eat -- hot items, cold items, made to order, cereals, fruits and other dairy, breads, muffins, etc.
The later you go for breakfast, the more chance selections will be minimized or gone.