Well in constructed if you know you want an Infantry, a Recon, and a Artillery and you have room for one enlist, this list helps you choose to take the Enlist Recon and Artillery for 45g savings over the Enlist Infantry and Recon which only saves 40g. Not a huge deal in the big picture but still worth the consideration.
This is obviously less useful in sealed where you have to work with what you get.
Edit: Also you can see top constructed players employing this information. For a while last month Witcher was using a deck http://www.battledexgame.com/game.php?game_id=23657
that had 2 Enlist Two Light Tanks and 1 Enlist Two AA, all of which save 50g each. Economics do make a difference.