The 504 Set-up Poster and World Checklist contains 2 promo items that were originally available at only Essen and BGG.CON 2015:

• Set-up Map - a promotional poster for 504 that shows the possible map shapes in full size. For an easy game preparation simply place the map tiles on this poster.
• World Checklist - a printed resource for tracking which worlds you've played.

Price: $5.04 - of course.