Ok, no, you only pay the 50 once. it means you get a spot in open beta, and that you get to D/L game 48 hours before it's availble in the store. Preorder is the same as retail except you get the ingame items to boot.
now more importantly... Helm in-game screenshots are Screenshots 21 and 1. 21 has a baddie sporting the Crab Spider (notice the position of the lights) and 1 has another baddie sporting the Wolf Spider helmet, laying on his back (again distinguishable by location of the red lights) There was one that might have Blood Widows helmet (red costumed villain on right in screen shot 6)
Hopefully this helps everyone out.