A FlyerTalk Posting Legend
Join Date: Sep 2009
Location: Minneapolis: DL DM charter 2.3MM
Programs: A3*Gold, SPG Plat, HyattDiamond, MarriottPP, LHW exAccess, ICI, Raffles Amb, NW PE MM, TWA Gold MM
Posts: 100,369
I usually see FAs collecting amenity kits and other items such as slippers from unoccupied F/J seats well before landing. I would assume that unopened items from occupied seats are similarly used on later flights. I would also assume that opened kits are discarded for hygiene.
I've also seen passengers ask for an additional kit as a souvenir and the FAs graciously providing them. These are garden variety kits; I've never seen a $300 or even $100 version.
Some hotels want you to take the branded toiletries home as they think this will remind you of a nice stay and want to come back.