I tried changing the marathon cost multiplier to 67 (same as quick speed) but that change is not reflected ingame for some reason...everything takes 3x the production cost, same as vanilla marathon, whats going on?
Edit : OK i had a backup gamespeeds-copy.xml in the folder and for some reason the game was using that instead of gamespeeds.xml. So once i moved the file out of the folder it worked.
The problem is that cost multipliers seem to affects the costs of everything and there doesnt appear to be anything in the gamespeeds.xml file that will let me edit the costs of buildings/units while increasing the costs of techs...