I'm looking for a word to describe artificially inflating a price to keep it consistent

Solution 1:

The word "markup" has been suggested in comments, with the response that "markup does work but in this case the price already has a markup which is distinct from this extra value".

This site about accounting suggests that while markup can simply mean "the difference between cost and the selling price" (ie. the difference between $1000 and $2000 in your example), there is a further meaning in retail of "the 'additional' markup from the original selling price [because of things like stock shortages and high demand]" (ie. the $200 you add to the price because of your supplier change).

So I'd suggested using the phrase "additional markup".