A Gilded 4-poster flatpack can be made at a workbench (Steel framed bench or better) in the workshop of a player-owned house. Like when making the normal Gilded 4-poster, this requires 60 Construction, uses 5 mahogany planks, 2 gold leaves 2 bolts of cloth, and gives 1330 experience. The flatpack can then be used on a bed hotspot in a Bedroom, either in building mode or not. This requires no Construction level and gives no experience.
The cost of making and selling a Gilded 4-poster flatpack from scratch gives a profit of: -77,724
After completing the hard Fremennik Tasks, hey can also be traded to Advisor Ghrim in exchange for 26,394 coins being added to your kingdom's coffers in Miscellania. See Flatpack: Miscellania reselling for details.