The problem is that not all the Arx people have accumulated are the ones that came free via the game there will be a large amount of Arx that were paid for.Maybe inflation is done in order to more quickly wipe out the current accumulation of ARXs over the years of play ?
Actually there is a second problem with this idea I and others with accumulated Arx from both sources will be looking at the new prices wincing and saying I am not paying that much, so the stockpiled will remain.