It would be lovely if there was a viable way of upgrading plot size without an enormous loss on one's gil purse. An idea I had was that company leaders could sell their plot and receive a key item, 'Refund Coupon' or something, which is equivalent to the value they initially spent on the plot of land or a large percentage at the least.

When purchasing a new plot of land, this coupon can be put towards the total cost of the new plot; the gil spent on the house will never re-enter the economy since the key item will have no resale value. When we bought our plot in Mist, it cost us 26m. We would love to put that 26m towards a Large plot now we have more funds available.

It would be nice, and it'd free medium plots up for other people trying to climb the property ladder! I see no real issue with this, providing the gil invested never re-enters the economy. This would maintain the gil sink design of housing whilst providing company owners the opportunity to realistically upgrade their house size.