I originally made this Excel Worksheet to help me figure out Fortification purchases in Solitaire ASL, but it should be a help for any DYO with Fortifications. All you need to do is enter the amount of points you have for Fortifications and then enter the quantity of each Fortification that you want. The worksheet does the math and keeps a tally of how many points you have left to spend. Makes it easy when you change your mind and want to pick something else - just enter the new quantities. The only thing is this will let you purchase multiple Booby Trap Levels (but you should know better).