it's a little frustrating that even with the maximum upgrades, the underwear and the ring you still only give them 35 luxury leaving you with them constantly demanding more from you and having to raise their loyalty and obedience every few days. if your lucky you can get a rare item that has added luxury on it
Viewing post in Luxury demands for Slaves
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.