Simply using the numbers from the first post:
lingerie +5
ring +10
private room +10
private room mansion upgrades +10
Better food +5
Personal bath +5
Cosmetics +5
Pocket money +10
Which sums up to a possible 60 total luxury given to a slave. Certainly enough to handle a demand of 40.
That said, yes, the first 4 items are the only ones that are a one-time only fee. And those max out at 35. So with a noble that does not have a trait to lower luxury demands, a player will need to give them at least 1 of the daily rewards which have a small recurring cost.