I understand they also partly as mortgages owned type a good half of the castles at least in southern France. Remember, the Middle Ages weren't really too much of a money economy for the most part; some merchant regions like northern Italy and the Low Countries aside "wealth" equaled "land"... And land was owned ultimately through fortifications. Philip's finances may not have gotten all that better, but he sure as Heck got the Templars off what was technically his turf (although I'd imagine he had to enfeoff most of it to various noblemen as per the feudal practice).