Extend auto-demolish

[Jojoya]

A lot of people also buy their housing items/don't craft themselves, so in that respect I believe that furniture could also be counted in the gil sink.

A gil sink removes the gil from the world economy completely. It's not just taking it away from one character so another character gets it.

Going to a vendor and buying housing items is a gil sink. Going to the marketboard isn't (outside of the transaction fee, if any) even if the player later loses/gets rid of the item.

If housing is truly intended as a gil sink, then there should be no refund of the purchase price for any reason (relinquish, relocation or auto-demo). Since 2 of those 3 do offer a refund of sorts, it's not really intended as a gil sink. The purchase price is more of a deterrent ("do you really want to be spending your gil on this instead of something else?").

A real gil sink would be a monthly property tax. Set it at 10% of the maximum plot value and paid to the resident caretaker. The lore explanation would be the fee is to pay the expense involved in maintenance and upkeep of the shared areas in the ward (the money to pay that lala groundskeeper near the Topmast has to come from somewhere). That would actually get players thinking twice about whether or not they really want that house after all if they will be continuing to pay for it.

[worldofneil]

Going to a vendor and buying housing items is a gil sink. Going to the marketboard isn't (outside of the transaction fee, if any) even if the player later loses/gets rid of the item.

If the player loses the item (due to demolition) that they originally paid gil for, how is that not a gil sink?

If housing is truly intended as a gil sink, then there should be no refund of the purchase price for any reason (relinquish, relocation or auto-demo).

Housing was added in 2.1 (14th December 2013) and when it came out was no demolition timer/reclamation of inactive housing. If you wanted to move house or transfer server your only option was to demolish the house and you would get back nothing of what you had paid.

Nearly two years later, housing reclamation was added in 3.1 (11th September 2015). At this point the 80% of your money came in, but it seems to me it's quite clearly compensation for having lost your house (otherwise they'd give you an option to sell to the system). I believe that's also why the caretaker only holds your items/gil for 35 days, because SE don't really want to give it back to you. To be an effective gil sink they have to never give it back, but that doesn't look very good for SE to go wiping out peoples property without giving them a chance to reclaim their items/money... hence the 35 days.

[Jojoya]

If the player loses the item (due to demolition) that they originally paid gil for, how is that not a gil sink?

A gil sink isn't "I no longer have the gil or the item I bought with the gil." A gil sink removes the gil from the game completely. It cannot re-enter circulation.

You might feel poorer because you personally no longer have that gil but someone out there does - unless they spent it on an actual gil sink. Aetheryte fees, MB fees, vendor items purchased with gil from the vendor - those are all gil sinks because that gil is removed from the game.