Someone asked in the original thread if the total cost included costs to decorate private rooms? The reply to that question was as follows:

As stated in the first 3 posts to this thread .... the "cost" is what it would cost you for opening all areas, HOSs, and ZZ .... as well as what it would cost you to craft every item the characters are requesting.......any cost you incur by spending extra to spin the Wheel additional times, play dice, buy furniture for your rooms, etc. is relative to each player..... and it is not a "game" cost. 

Most players will not actually be paying that entire cost because they will have won some crafted items from the Wheel of Fortune, friends might gift a few, and those who have feeder games can send them to their main game. 

The "reimbursements" mentioned in the total at the end of the cost posting ONLY contains the amount of coins you get back from the characters and Pinfeathers when you complete quests..... that is a concrete amount..... all players get that. 

However, the reimbursement does not include any coins you get as a bonus from crafting, bonus coins when you reach each stage of the HOS completion toward max, coins you may get from pets, coins from the Wheel (hitting the stars), coins from morphing flowers, etc......... these are all relative and will not be the same for each player, so they cannot be computed/tallied. 

Hope this helps to further explain.