So what your saying is that for every XIP token bought the supply of Xfuel/XBY will be reduced by 1k or those will be Locked away ? if not you are effectively adding 1k of those tokens for every XIP sold.
Let me give you a better example for you to understand.
If you buy a regular share using USD, is that USD being taken out of circulation and does that share become a means to pay your bills? No the USD goes to the seller and if you need the money your share is worth you need to sell it for USD. The same applies for tokenised shares, they are not coins and you need to sell them if you want to spend the money they are worth.